Each day, two kindhearted suburban stepbrothers on summer vacation embark on some grand new project, which annoys their controlling sister, Candace, who tries to bust them. Meanwhile, their pet platypus plots against evil Dr. Doofenshmirtz.
Rollercoaster
While their mother is out shopping, the boys build a roller coaster. Dr. Doofenshmirtz and Perry battle due to the doctor's evil plan of throwing the earth off its rotation.
Lawn Gnome Beach Party of Terror
Phineas and Ferb's newest backyard project is to create a tropical beach paradise. Meanwhile, Perry tries to stop Dr. Doofenshmirtz's plan to steal all the garden lawn gnomes.
Flop Starz
Phineas and Ferb decide to become a one hit wonder, Phineas and the Ferb-Tones and Candace wins the chance to sing with them. Meanwhile, Perry must stop Doofinshmirtz's giant robot - disguised as a temp.
The Fast and the Phineas
Phineas and Ferb enter the family car in an auto race, while Candace has to bust them and impress Jeremy. Meanwhile, Perry must stop Dr. Doofenshmirtz from deflating every inflatable object in the tri-state area.
Lights, Candace, Action!
Upon hearing that her favorite play is being made a movie, Candace rushes to try for the lead, only to see that Phineas and Ferb have become the directors and changed the script to include a little more insanity. Meanwhile, Perry goes to Doofinshmirtz Evil Inc. to find out why Heinz has been so quiet lately.
Raging Bully
Phineas enters a thumb-wrestling competition with a local bully, while Doofenshmirtz creates a hypnotic device to control people's minds so they will sing him Happy Birthday.
Candace Loses Her Head
Phineas and Ferb decide to carve Candace's face into Mount Rushmore for her birthday present, while Perry attempts to stop Doofenshmirtz from making a tunnel to China.
I, Brobot
Phineas and Ferb clone themselves so they can complete more projects while Doofenschmirtz hovers over his girlfriend's house with a huge magnet to erase crazy messages on her answering machine, for the sake of recording new ones.
Run Away Runway
Candace becomes a model, and is forced to wear outfits designed by Phineas and Ferb while Doofenshmirtz designs a machine to create clones of himself, to avoid having to wait in line.
The Magnificent Few
When Doofinshmirtz unleashes his army of termites to eat all the wood in the tri-state area, Phineas and Ferb use their newfounded love of a cowboy life to herd the stampeding cattle back to the carnival, but with Agent P stuck in a room filling with lava, how will he survive?
S'Winter
The boys use a sno-cone machine to create a Winter paradise during the middle of Summer in their backyard, Candace tries to pursue Jeremy (who thinks dropped her for a Swedish exchange student), and Doofenshmirtz tries to melt chocolate with a machine made from laser pointers.
Jerk De Soleil
The boys create a circus for the neighborhood after their original circus plans are canceled, while Jeremy gives Candace wild parsnips which she is allergic to. Doofenshmirtz creates a device to make people's voices higher so his own voice will seem lower.
Are You My Mummy?
Phineas and Ferb visit an Egyptian-themed movie theater and attempt to get a mummy of their own, but they end up capturing Candace, who is wrapped in toilet paper, while Doofenshmirtz tries to raise the city's water level so his real estate will become beachfront property.
Ready For The Bettys
Ferb and Phineas accidentally discover Perry's secret lair and are thrust into a spy mission of their own. Meanwhile, Candace travels on a tour bus with a girl band called "The Bettys"
I Scream, You Scream
Phineas and Ferb make the biggest ice cream maker for Isabella after her tonsils are taken out. Doofenshmirtz's daughter, Vanessa, spends the day at his lair and tries to convince his ex-wife that he's evil.
Toy to the World
Based on the fact that a platypus doesn't do very much, Phineas and Ferb create a wooden toy version of Perry to sell to a toy company. Meanwhile, the real Perry heads off to stop Doofenshmirtz from building the Great Wall of the Tri-State Area and starting up toll booths at the only exits.
Get That Bigfoot Outa My Face!
Candace and the boys visit their grandparents at a lake house and the boys try to scare her with a fake Bigfoot while Doofenshmirtz goes out on a date and Perry gets ends up in the middle of it.
It's a Mud, Mud, Mud, Mud World
Phineas and Ferb create a monster truck for Candace to practice driving while Dr. Doofenshmirtz tries to find investors for his line of monster trucks that are actual monsters, with a trump card to take down the competition.
Mom's Birthday
Candace plans a special birthday for Mom, and even a song, but Phineas and Ferb are always getting in her way of what she planned, unintentionally topping everything. Meanwhile, Doofenshmirtz creates a shrinking machine that will make whatever he hates implode.
Journey to the Center of Candace
When the boys build a shrinking submarine to retrieve Isabella's sash from Pinky's stomach, they end up in the wrong place.
It's About Time!
Phineas and Ferb find a time machine at a museum and travel back to the Jurassic Age. Meanwhile, Perry is sad when Doofenshmirtz replaces him with a new nemesis, Peter the Panda, so he confides in a relationship talk-show host.
Dude, We're Getting the Band Back Together
The boys and Candace hatch a plot to reunite their mom and dad's favorite band for a wedding anniversary concert.
Tree to Get Ready
Phineas and Ferb build super tree houses for themselves and Candace, but things get a little out of hand when a treehouse fight instigates. Meanwhile, Dr. Doofenshmirtz plans to ruin a ceremony in his brother's honor.
The Ballad of Badbeard
The boys set out on a high-seas adventure after learning about a mysterious pirate from their grandpa. Meanwhile, Candace spies Perry and Dr. Doofenschmirtz up to their old tricks, but is it all in her head?
Greece Lightning
The boys stage a chariot race through the town's streets after learning about ancient Greece. Meanwhile, Dr. Doofenshmritz creates a giant robot named Norm to destroy Perry, once and for all.
Leave the Busting to Us
Candace uses a reality show to secretly film her brothers designing a white-water rafting ride. Meanwhile, Perry must crush Doofenshmirtz' dream of becoming a magician, as well as dominating the tri-state area.
Crack That Whip
Phineas and Ferb set up a roller derby rink for Grandma Betty Jo.
The Best Lazy Day Ever
Phineas and Ferb decide to do absolutely nothing for the day. Candace questions her purpose in life after realizing that she can't bust her brothers for doing nothing. Meanwhile, Dr. Doofenshmirtz is tired of being the ugliest person around, so he invents a device that can turn anything and anyone ugly.
Boyfriend From 27,000 B.C.
While on an archaeological dig, the boys discover a caveman who falls in love with Candace, who is dressed as a cave girl for costume party. Then, Phineas and Ferb assist Buford in locating his missing goldfish.
Voyage to the Bottom of Buford
When Buford's goldfish goes missing, the boys help him find it out at sea. Meanwhile, Dr. Doofenshmirtz tries to destroy a tape of him 'saving' a kitten from a tree.
A Hard Day's Knight
Phineas, Ferb, and Candace go to a Renaissance festival and Phineas and Ferb get Candace to go into a jousting tournament.
Traffic Cam Caper
Perry wants to destroy footage from a traffic camera to keep his identity a secret, as Candace tries to use the film in hopes of proving her brothers create unusual stuff. Then, the guys decide to build the largest bowling ball and pins in the world, while Doofenshmirtz wants to rid the world of rainbows.
Bowl-R-Rama Drama
Phineas and Ferb build the world's largest bowling ball and pins. Meanwhile, Doofenshmirtz wants to use his latest invention to freeze the Tri-State Area so the people will buy his hot chocolate.
Got Game?
The guys decide to hold a competition between the girls to see which are better at sports. Also, the build a telescope in the backyard. Then, Jeremy's sister is tormenting Candace. Doofenshmirtz wants to be the winner of a dog show, and makes an attempt to liquefy a steak.
Comet Kermilian
The boys build a telescope, while Doofenshmirtz tries to liquify steak. Meanwhile, Candace has another encounter with Jeremy's younger sister, Suzy.
Put That Putter Away
Phineas and Ferb create the world's largest golf course, and since Candace is sick, she asks her best friend Stacey to bust the boys for her.
Does This Duckbill Make Me Look Fat?
Phineas and Ferb create a teleporting machine, but it ends up switching Candace and Perry's brains.
The Flying Fishmonger
The boys are helping Ferb's grandfather live his life long dream - to jump a gorge in his motorcycle, the Holy Mackerel. Meanwhile, Perry sets out to stop Dr. Doofenshmirtz from exacting another petty revenge that dates all the way back to the sandbox.
One Good Scare Ought to Do It!
When Isabella falls prey to hiccups, Phineas and Ferb gather the kids together to help scare them out of her, using a remote controlled haunted house. Meanwhile, Doofenshmirtz sets out to destroy his mentor's hideout, so that no one could discover his secrets, but not if Perry has something to say about it!
The Monster of Phineas-n-Ferbenstein
The boys learn about one of Ferb's Victorian ancestors, who helped a scientist create a monster. Meanwhile, Doofenshmirtz recalls the story of his great-great-grandfather Dr. Jekyll Doofenshmirtz.
Oil on Candace
When Django feels down for not being able to draw art on the same scale as his father, Phineas and Ferb get some big ideas for his piece and the famous "unpainted desert". Meanwhile, Perry faces off against Doofenshmirtz, as he does his best to impress his visiting evil professor.
Out of Toon
The boys create a cartoon and cast themselves as superheroes and Candace as the villain, while Perry attempts to defeat Doofenshmirtz, who has taken control of the power of dance.
Hail Doofania!
When Doofenshmirtz's brother Roger is elected mayor, he decides to build his own country, where he can rule over everything, but how will he stop him when Perry is having trouble entering his hideout? Meanwhile, Phineas and Ferb, in an attempt to help Isabella see her "first" rainbow, create the Rainbow-enator, which harnesses the power of their breakfast cereal to make the light show. The strangest anomaly of the episode, however, is when Candace and Vanessa manage to get their clothes mixed up at the dry-cleaners, resulting in a backwards day for everyone.
Out to Launch
The boys build a rocket ship to get a good look at a star named for them, and Candace accidentally takes a ride with them just as she is trying to find the courage to ask Jeremy to a dance, while Isabella tries her best to do the same with Phineas. Meanwhile, Perry must stop Dr. Doofenshmirtz, who, not only is conveniently in space too, but has created a massive spacestation in an attempt to get revenge on "Huge-Hands-Hans".
Phineas and Ferb Get Busted
After taunting the boys for going to search for the "Lake Nose Monster", Candace begins freaking out on her lifeguard job, seeing the monster at every turn. Meanwhile, Dr. Doofenshmirtz tries to remove all the zinc from the lake, though even he's not sure why.
Unfair Science Fair
Phineas and Ferb help Baljeet build a portal to Mars for a special Summer science fair. Candace competes against another girl for getting a job at Mr. Slushy Burger. Meanwhile, Doofenshmitz builds a bicarbonate volcano for the science fair, in yet another attempt to redeem himself from his embarrassing childhood, where we discover where the -inator suffix originated from.
Unfair Science Fair Redux (Another Story)
When Candace believes that no one wants to be around her anymore, she quickly steps through Baljeet's portal to Mars, where she is quickly heralded among the martians. Meanwhile, Perry accompanies Dr. Doofenshmirtz to help build his evil contraption for him to stop faster, with slightly less than pleasing results.
