The film is a lighthearted reference of 1950s melodramas about the sufferings of substance abuse and drug recovery groups such as Alcoholics Anonymous.
The short opens with Sylvester once again attempting to catch and eat Tweety, this time succeeding and closing the blinds to hide the evidence. Before he can eat Tweety, however, he is interrupted by a crimson, erudite, milquetoast cat (named "Clarence" or "Sam" in some sources but unnamed in the short itself), who tells him that his constant cravings for Tweety are a sign of profound personal weakness, and that the only way for him to overcome this weakness is to kick the habit for good. Believing that he is in need of help, Sylvester proudly joins "Birds Anonymous", a group of cats who have banded together to overcome their addictions to birds. Sylvester lives by this motto: "Birds is strictly for the birds!"
However, Sylvester's resolve begins to break down after a short time, primarily due to constant temptation since he still lives in the same house as Tweety. The temptations begins to grow even more after he hears TV commercials featuring a stuffed turkey and bird-themed songs on the radio. Sylvester valiantly makes many attempts to control his baser urges, even physically chaining himself to an iron radiator at one point. After Tweety asks the cat: "Don't you wike me anymore?" Sylvester replies: "I think... I think... I think you're... I think you're... DELICIOUS!" and yanks the radiator out of the floor as he makes another grab for Tweety, only to be stopped by his cat friend again (with a plunger to his mouth) who expressed concern that Sylvester was weakening. Sylvester admits he did and thanks his friend for the intervention.
Sylvester is tortured by insomnia that night, and eventually succumbs to his basic instincts to try to grab Tweety, but is stopped again when his cat friend pours alum in his mouth. Sylvester then attempts to literally drink Tweety through a straw but fails. Ashamed of his weakness, Sylvester collapses into sobs ("I can't stand it! I gotta have a bird! I'm weak! I'm weak, but I don't care! I can't help it! After all, I am a pussycat!"), but the cat friend consoles him, telling him severe withdrawal symptoms are all part of the process, and that if he stays with the "Birds Anonymous" program, he will eventually succeed and come to love birds, as he does. However, when the cat kisses Tweety to prove his point, years of his denial take their toll and the B.A. cat attempts to devour Tweety himself, this time with Sylvester restraining him and telling him to control himself.
Tweety, escaping to a nearby counter, watches and sums up the whole affair with a shrug: "Like I said before: Once a bad ol' puddy tat, always a bad ol' puddy tat!"
The voice of the erudite, milquetoast cat's (retroactively named Clarence in modern Looney Tunes comics) sounds similar to Marvin the Martian (the creation of the junior Termite Terrace director, Chuck Jones). The voice of the second B.A. Cat was used by Blanc for the love-bird in Life With Feathers, among other places.
The premise of this cartoon was adapted into The Last Hungry Cat later with Sylvester trying on his own to get rid of his hunger for Tweety.
Birds Anonymous won the Academy Award for Best Animated Short Film in 1957 beating Tabasco Road starring Speedy Gonzales and his drunk friends; both shorts were eventually given Blue Ribbon reissues in 1961. When Eddie Selzer died, the statuette was passed on to Mel Blanc, who said that this was his favorite cartoon to do voices for, especially when it came to Sylvester.
This film appeared in The Looney Looney Looney Bugs Bunny Movie's third act "The Oswalds" where Sylvester and Clarence fight over Tweety again with Granny intervening.
As of 2005, Birds Anonymous can also be found, uncut and restored, on the Looney Tunes Golden Collection: Volume 3 and on Warner Bros. Home Entertainment Academy Awards Animation Collection. It can also be found on the former UK rental VHS tape of The Bodyguard from 1993. A music/effects only track is also available.