[[caption-width-right:320:''Magazine/{{Mad}}'s'' Jack Davis is drawing us for the ''Magazine/TVGuide'' cover? Very impressive, Mr. Kot-tair!]]

->''"Hey, Julie.... did I ever tell you about my [[EndOfEpisodeSilliness Uncle Fremont Kotter]].....?"''

Long before Jerry Series/{{Seinfeld}} wondered about airline peanuts, before Creator/TimAllen said his first [[Series/HomeImprovement "Arrr arrr arrr!"]], before Series/{{Roseanne}} became a Domestic Goddess, there was Gabriel "Gabe" Kaplan, one of the very first stand-up comedians to successfully [[SitComic turn his comedy routines into a hit TV sitcom]]. ''Welcome Back, Kotter'' ran on Creator/{{ABC}} from 197579. The series was based on Kaplan's own high school experiences with remedial education and his memories of a teacher who cared dearly for her students.

The premise: Gabe Kotter returns to Brooklyn's James Buchanan HighSchool as a teacher and is assigned the [[DustbinSchool remedial class of "Sweathogs"]] to which he once belonged. Mr. Kotter is an involved and caring teacher, which one would have to be in dealing with a certain four students in his class, who end up in trouble on a regular basis: ladies' man Vinnie Barbarino (played by breakout star Creator/JohnTravolta), the always cool Freddie "Boom-Boom" Washington (Lawrence Hilton-Jacobs), the tough [[OverlyLongName Juan Luis Pedro Phillipo de Huevos Epstein]] (Robert Hegyes), and the sheepish Arnold Dingfelder Horshack (Ron Palillo). Kotter frequently finds himself butting heads with cantankerous vice principal Mr. Woodman (John Sylvester White), who dismisses the Sweathogs as a lost cause, and tries to juggle his teaching life and his home life with his wife Julie (Marcia Strassman).

Changes on the show: Gabe Kaplan was absent from much of the fourth season due to creative differences with executive producer James Komack, whom Kaplan openly felt was not serving the show's best interests. Kotter was made vice principal, and thus was seen considerably less frequently. John Travolta, of course, found his own place as a celebrity, leaving the show around the same time Gabe Kaplan did (returning every so often as a "special guest star"). The replacement for Barbarino was Beau, who didn't help things much. By now the show had essentially lost its two biggest stars.
!!''Welcome Back, Kotter'' contains examples of:

* AndStarring: John Travota's billing during his last season on the show.
* BabiesMakeEverythingBetter: Julie gives birth to twin girls.
* BerserkButton: Don't say anything bad about Barbarino's mother.
-->'''Barbarino:''' Hey! NOT my mother. That woman's completely holy!
* BigScrewedUpFamily: Juan Epstein.
-->'''Epstein''': I don't have to stay here and be ignored! I have nine brothers and sisters. If I want to be ignored, I'll just go home.
* CantGetInTroubleForNuthin: Beau [=DeLebarre=] tries to prove he's not an ass-kisser by playing a prank on Mr. Woodman, but Mr. Woodman refuses to believe it was him and yells at the Sweathogs instead. Luckily, he ''does'' manage when he admits to Woodman he read his student file, which is forbidden.
* CatchPhrase: "Up your nose with a rubber hose" (everyone), "Hi, there" (Washington), "Heyyyy Misssster Kotttaire!" (Washington),"What?" "Where?" (Barbarino), "I'm so confused!" (Barbarino), "Ohhh ohh ohh ohh!" (Horshack), "Very impressive, Mr. Kotter!" (Horshack)
* CharacterDevelopment: Most notably Horshack (went from the TagalongKid to a young man willing to stand up for what he believed in and the first Sweathog to marry), Julie (went from Gabe's mildly frustrated but mostly supporting wife to a major presence at the school) and Barbarino (went from a directionless skirt-chaser to working as a hospital orderly).
* CloudCuckoolander: Everyone had their moments, but Horshack is ''the'' definitive example.
* CommutingOnABus: Mr. Kotter's appearances in the last season were very sporadic, as Kaplan had become discontent with the direction of the show. Mrs. Kotter becomes the new mentor of the Sweathogs.
* DeanBitterman: Mr. Woodman
* DistaffCounterpart: Arnold has a one-episode friend named Goldie who acts and laughs quite a bit like him.
* DustbinSchool: The "Sweathogs" was the nickname of a class like this at James Buchanon High in Brooklyn. Gabe Kotter had graduated from this class and gone on to become a teacher. He volunteered to return to his old high school and teach this class, hoping to help kids who were in the same position he had been in in high school. They are viewed as a lost cause by Woodman.
* EarlyInstallmentWeirdness: In the pilot, Horshack is implied to be a CovertPervert who apparently wasn't allowed to talk unless Barbarino told him to. Barbarino also seemed to have a regular sweathog-girlfriend. The Sweathogs were actually a tad more intimidating.
** Epstein was known as the toughest student in the school, and voted "most likely to take a life". As time went on this trait was phased out and he was more of a smartass.
* EndOfEpisodeSilliness: Formerly the TropeNamer when it was called "Uncle Herbie".
* EnterStageWindow: The Sweathogs routinely drop in on their favorite teacher via his living room window. Doesn't bother him any, but his wife doesn't like it.
* EveryEpisodeEnding: Gabe tells Julie an amusing anecdote about one of his many relatives at the end of every episode.
* FakeGuestStar: Creator/JohnTravolta during the final 1978-1979 season, due to becoming a movie star with leading roles in ''Film/{{Carrie}}'', ''Film/SaturdayNightFever'', and ''Film/{{Grease}}'', still managed to reprise his role as Vinnie Barbarino on a part-time basis.
* FourTemperamentEnsemble: Kotter (phlegmatic/sanguine), Washington (sanguine), Barbarino (choleric), Principal Woodman (choleric/melancholic), Julie (melancholic), Horshack (phlegmatic), and Epstein (leukine).
* GRatedDrug: In the episode "What Goes Up ... ", Freddie becomes addicted to painkillers (to heal a basketball injury); a naive Horshack takes Freddie at his word that said pills are "vitamins," while the others are well-aware that Freddie is becoming dependent on them.
* Creator/GeorgeCarlin: Guest starring as radio DJ Wally the Wow, and as Wally the Weasel, a former Kotter-era Sweathog.
* TheGhost: Principal Lazarus.
* IceCreamKoan: The mantra of the cult which Horshack temporarily joins while in pursuit of a girl [[BuxomIsBetter who can really fill out a sheet]].
--> What is, is. What was, will be. What will be ''was'' but will be again.
* NeverWinTheLottery: In one episode Kotter chips in a quarter for the Sweathogs weekly lottery ticket when one of them comes up short. When the ticket then wins, the Sweathogs try to just give Kotter back his 25 cents instead of a share of the winnings.
* NobodyTouchesTheHair: Barbarino is like this.
* OnceAnEpisode: Kotter tells a joke about one of his relatives.
* TheOneWhoMadeItOut: Gabriel.
* ParentalSubstitute: Gabe often acted like this for the guys, especially Arnold.
* PersonalitySwap: Occurs with Kotter and Woodman in Season 1's "No More Mr. Nice Guy", when Woodman briefly resumes teaching and become a CoolOldGuy for a day, even briefly becoming more popular than Kotter, while Mr. Kotter turns grumpy and loses his cool, ordering the Sweathogs to return the stolen chalk back to Mr. Woodman.
* RealLifeWritesThePlot: One two part episode had Kotter trying to start a stand up career.
* RunningGag: Epstein's never ending supply of excuse notes, almost always signed "Epstein's Mother".
** Horshack's very enthusiastic hand-raising in class: "Ooh! Ooh! Ooh! Mr. Kotter!"
** Barbarino's [[ObfuscatingStupidity "What?" "When?" "Where?"]] when Kotter or Woodman is looking for answers to a situation.
** Julie's infamous tuna casserole.
* SlapSlapKiss: Vinnie had some of this with Judy Borden in the early seasons, even dating for a short time.
* SignatureLaugh: Horshack's asthmatic laugh.
** AnnoyingLaugh: ... and boy was it a doozy.
* StudioAudience
* SuspiciouslySimilarSubstitute: Beau De Lebarre as Vinnie's replacement.
* ThematicThemeTune: In fact, the producers of what was originally going to be called ''Kotter'' thought John Sebastian's "Welcome Back" captured the tone of the show so well they renamed the show after it.
* ThemeTuneExtended: "Welcome Back" was originally just one verse. [=DJs=] suggested recording a full-length version to Sebastian. He did, and it became a #1 hit.
* TransatlanticEquivalent: The UK sitcom ''Please Sir!'' which predated this one. Some British viewers believe ''Welcome Back, Kotter'' is in fact an uncredited remake, but while the shows have similar premises no one's ever been able to prove plagiarism.
* TranslationMatchmaking: In Italy it's known as ''I Ragazzi del Sabato Sera'' (''Saturday Night Guys''), after ''Film/SaturdayNightFever''.
* TwoferTokenMinority: Puerto-Rican Jew Juan Epstein.
* UglyGuyHotWife: Gabe and Julie, though Gabe is more plain/quirky-looking than ugly.
* VerySpecialEpisode: "What Goes Up," the Season 3 episode where Boom Boom got addicted to painkillers to heal a basketball injury. Boom Boom is in deep denial, and so is a shaken Horshack who naively believes Boom Boom's explanation that the pills are "vitamins." The others aren't so fooled and eventually get Boom Boom to realize what he's doing. In the final season, "Come Back, Little Arnold" has Horshack using booze to boost his courage when asking out a new love interest. He snaps out of it after he accidentally punches her out while aiming for one of the guys. Both of them are back to normal by the following episodes.
* WrittenInAbsence: As explained above, Kotter was promoted to vice principal in season 4 and appeared less frequently due to Kaplan's feud with executive producer James Komack.