Factual error: During the scene where Mozart is being carried away in his coffin by horse and cart there is a brief shot where he is being taken down a muddy path and a farmer is seen with his cows. If you look closely to the left side of the screen you can see a large overhead power line. If you look even more closely you can even see the wires coming out of the pylon. The movie is set in the 18th century and obviously it obviously should not be there.
Visible crew/equipment: When Mozart and family visit a parody on several operas of his in a public theater, in one part of the show little people appear from all sides of the stage. When the last of the little people (carrying a model of horse) hops through a paper wall on the side of the stage, you can see a man in jeans walking behind the set.
Continuity mistake: In the extended version of the DVD, there's a scene where Constanza goes to sleep with Salieri. In one shot there's a very prominent candle next to or just behind her on her right that smoking like it's just been extinguished. But from the front view there are no candles that close to her, and the ones a short distance away are all lit.
Trivia: 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.
Trivia: 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.