An Ivan Reitman prank to have some of the characters drag Warren Oates' character into the mud during the obstacle course scene, led to Oates chipping a tooth and Reitman getting a tongue lashing from Oates.
The cast improvised virtually all of the dialog where they sit around and tell their back stories. This includes Murray's lines about 'Lee Harvey' making out with a cow and calling Sgt. Hulka a 'big toe'.
According to Ivan Reitman in the DVD Commentary, the scene where Bill Murray is loading the rich woman's suitcases into the trunk and he hits himself in the crotch was accident. Murray really did hit himself in the crotch with the case, thus his very real line "Oh, my balls."
According to Ivan Reitman, Bill Murray insisted 'Harold Ramis (I)' be cast as his friend for two reasons: 1. They were long time friends in real life. 2. So Ramis could help Murray re-write his dialog or help him improvise.
The scene the morning after John Winger and MP Officer Stella Hanson had sex in General Barnicky's house, when they emerge from the trunk, is actually a lift from a cut scene when the guys and girls meet up in Germany. This lift is now something of a continuity error in the Special Edition DVD where those cut scenes in the German Hotel are now restored. You can tell this because if you watch the decor of the General's bedroom and Winger and Hanson's wardrobe, it's the same clothing they're wearing in their German Hotel Suite and the General's decor and the suite are the same.
The last sentence the platoon shouts during their performance at graduation, "the quick brown fox jumps over the lazy dog", is a sentence that was popularly used to test typewriters and telegraph machines because it contains every letter of the alphabet at least once.
According to the DVD special features, the film was originally conceived as a vehicle for Cheech & Chong; Ivan Reitman has also stated that the reason this fell through was because their manager insisted (without the pair's knowledge) on a 25% share of Reitman's next five films, which he wasn't willing to give up. The script was then rewritten for Bill Murray and Harold Ramis, and most of the "stoner" humor was shifted to the "Elmo" character played by Judge Reinhold.
John Winger's use of the phrase "We are the wretched refuse" to describe how the platoon was made up of men from around the world is a reference to a poem, "The New Colossus", by the nineteenth-century American poet Emma Lazarus. "The New Colossus", describing the Statue of Liberty, appears on a plaque at the base of the statue.
According to Ivan Reitman in the DVD Commentary, Columbia Pictures wanted to cut out the scene where Sgt. Hulka and John Winger have a confrontation in the latrine. They felt the scene was 'too serious'. But Reitman insisted that it be left in to truly establish Sgt. Hulka's strength and authority.
John Larroquette improvised the dialog where he's watching the girls in the shower through the telescope, including the odd line "Oh, God! I wish I was a loofah!" According to Larroquette, he had to explain to Reitman what a loofah was.
'Do Wah Diddy Diddy', a central theme performed by cast members, was originally recorded in the US by The Exciters in late 1963. During "The British Invasion" it was covered by Manfred Mann and rose to #1 US Pop in July 1964. The song has become a popular cadence in the US military.
The Basic Training scenes were filmed at Fort Knox, Kentucky. Fort Knox is home to the U.S. Army Armor Center, which trains new tank crewmen and armored cavalry troopers. The barracks in the film are still at Fort Knox, but they've been gutted and converted into an urban warfare training course. As of 2010, the United States Army Armor School is being moved to Fort Benning, Georgia as part of the United States' BRAC program.
Basic training in Stripes takes place at the fictional "Fort Arnold" which was actually a fort during 18th century. It was named for General Benedict Arnold. After General Arnold was branded a traitor "Fort Arnold" was renamed "West Point".