"Lux Radio Theater" broadcast a 60 minute radio adaptation of the movie onOctober 13, 1941 with Bud Abbott and Lou Costello reprising their film roles.
Bud Abbott and Lou Costello's drill routine ran only two-and-a-half minutes in the script, but was allowed five minutes of screen time because of their ad-libbing. In fact, much of their dialogue in the film was ad-libbed.
A sneak preview was held in late January 1941 for soldiers at Fort MacArthur, California.
Although Arthur Lubin was a contract director at Universal, on a set weekly salary, this film was such a huge hit ($4 million gross on a $180,000 budget) that Universal gave him a $5,000 bonus.
During WWII, the Japanese used to show the sequence "Drill Routine" from this movie to show how stupid the American Army was.
Grossing over $4 million, this film gained more money than any film Universal Pictures had produced to that point.
In the beginning of the movie when Bud Abbott' and Lou Costello are about to go into what they think is a movie theatre, Lou asks the recruiter who's standing outside the door what movie is playing. The recruiter replies, "You're in the army now." There was actually a movie by that title, You're in the Army Now, that starred Phil Silvers and Jimmy Durante released by Universal that same year.
The train whistle blows Lou Costello's catchphrase, "I'm a bad boy".
This film marks the first time that Lou Costello's brother, Pat Costello, served as Lou's stunt double. He earned $31 a day for his work.
This film took in $4 million (at a time when theater admission ranged between 10 cents and 25 cents), more than either Citizen Kane or How Green Was My Valley.
This was the first of three consecutive film collaborations between Bud Abbott, Lou Costello and The Andrews Sisters.