- Directors: John Landis
- Producers: Ivan Reitman, Matty Simmons
- Writers: Harold Ramis, Douglas Kenney, Chris Miller
- Genres: Comedy, Romance
- Actors: John Belushi, Tim Matheson, Peter Riegert, John Vernon, Verna Bloom, Thomas Hulce, Cesare Danova, Donald Sutherland
Two freshmen, Larry and Kent, are trying to get accepted to a fraternity at fictional Faber College in 1962. They first try their luck at the Omega Theta Pi House invitational party but are repeatedly steered to an area with other undesirables. They then try next door at the Delta Tau Chi House, where Kent’s brother was once a member. They meet John “Bluto” Blutarsky, urinating outside the building. The Deltas “need the dues”, so Larry and Kent are allowed to pledge Delta. They are given the fraternity names “Pinto” (Larry) and “Flounder” (Kent).
Meanwhile, Dean Vernon Wormer is trying to remove the Delta fraternity from campus due to repeated conduct violations. Since they are already on probation, he puts the Deltas on “Double Secret Probation” and orders the clean-cut Omega president Greg Marmalard the job of finding a way to get rid of the Deltas once and for all.
At the campus ROTC detachment drills, Doug Niedermeyer, the cadet commander, berates Flounder for wearing a pledge pin on his uniform. Later, he orders Flounder to clean his horse’s filthy stable stall. While practicing their golfing, Deltas Boon and Otter become annoyed when they overhear Doug bullying Flounder. (“Only we can do that to our pledges!”) After Boon takes a few swings with his driver, Otter shows him what he is doing wrong. His first ball strikes Doug’s horse. the second hits Doug in the head, knocking him out the saddle; terrified, the horse takes off, dragging a screaming Doug behind it. Bluto and D-Day then talk Flounder into sneaking the hated animal into Dean Wormer’s office late at night. They give him a gun and tell him to shoot it. Unbeknownst to Flounder, the gun is loaded with blanks. He cannot bring himself to kill the horse and fires into the ceiling, but the noise so frightens the horse that it dies.
The Deltas’ midterm grades are so bad that they are all expelled from school by an ecstatic Wormer and their draft boards are notified of their eligibility. For revenge, the Deltas decide to wreak havoc on the annual homecoming parade, inspired by Bluto’s impassioned speech. In the ensuing chaos, Bluto steals a car, abducts Mandy and drives off into the sunset, or rather to Washington, D.C., as the futures of many of the main characters are revealed.