Factual error: Many of the vehicles in the movie have Pennsylvania inspection stickers on the lower driver's side windshield. This is not surprising being that most of the movie was filmed in Pennsylvania. However, they should have been removed when the car is suppose to be from another state. For example, the Senator's daughter, just before her abduction in Tennessee, is seen driving a car with Pennsylvania inspection stickers. Also, the driver for Yourself Storage in Baltimore also has Pennsylvania stickers on his car.
Continuity mistake: When they find out Lecter is on the elevator, they look down the shaft at him and there is quite a lot of blood on his back, so much that it even reaches down to his belt. However when they open the elevator shaft and the body falls down, there is only a small amount of blood on his back.
Continuity mistake: While travelling from the post mortem examination, Clarice is in the back seat speaking to her boss. In going back and forth in conversation, her hair changes from being curled up to being curled under, all in one swift change. This is a different style and not done as could be by running your fingers through your hair as the camera cut away.
Revealing mistake: When Clarice is at the archive, she sees two articles, one entitled "Baltimore Psychiatrist Receives Highest Honor" and "New horrors in 'Cannibal Trial'." The column beneath both titles to the right is exactly the same, and in the first article, that same column is repeated at the leftmost and rightmost columns and in the second, is repeated at the rightmost column. That same column is scattered on every article she sees.