The producers purposely went with relatively unknown actors for the film, because they thought they'd be more believable than stars who people already identified in different roles.

The actors in the film are never actually heard playing the keyboard instruments. The actors played the keyboards in time to recorded music being played on set or via earphone. However, in order to avoid mistake watchers noticing it, the actors had to learn the pieces, so that they are almost always playing the right keys for the music.

Not until the director's cut of the movie do we understand why Constanze Mozart is so short with Salieri just before her husband's death, coldly demanding that he leave the house. For rating and length reasons, a nude scene of considerable length in which Constanze undresses, presumably to sleep with Salieri, only to have him show her the door, was not included in the theatrical version. That is because when Salieri is having his flashback, he prays that he will become a great composer and offers his chastity towards achieving that goal.

In the scene where the dying Mozart is dictating his music to Salieri, Tom Hulce would deliberately skip parts of his lines which F. Murray Abraham needed to continue his part of the dialogue. Hulce didn't tell Abraham that he was going to do this, so when Salieri is scrambling to keep up and tells Mozart that he's going too fast it was a genuine reaction. Hulce has said that he did this partly to portray Mozart as delirious from his illness, and partly to portray Salieri as less talented. Confirmed on the director's cut DVD.

Mozart and Salieri are shown conducting standing in front of the pit. In their times however, they would have conducted from a harpsichord in the pit.

Before the production crew decided on an American cast, a very young Kenneth Branagh was signed to play the title role.