Continuity mistake: When Brooks has the knife to Heywood's throat, in one shot there is blood visible on his neck, yet in the next shot the blood is gone. (00:54:15)
Continuity mistake: When Andy is playing the opera music, the whole prison stops what they're doing and stares at the speakers. When they show the infirmary, an African American man gets out of bed and looks out of the window. When the camera goes to the prison yard it pans around and goes right across the same African American man, who is now standing in the yard. (01:06:05)
Continuity mistake: When showing how Andy switches the books, watch the folder on the table. The folder has a corner that is bent up. When Andy removes the Bible and folder from behind his back and places then on the table, the folder he places has the bent corner. The one already on the table is perfectly flat.
Continuity mistake: As Norton kills himself, the glass that blows out behind him is quite large and about half of the frame gets blown out. There are a few specs of blood on the window as well. A couple of shots later as the camera pulls back and shows Norton you can see the hole in the window is quite small and shaped differently and a smear of blood above the hole now. (02:03:40)
Continuity mistake: In the scene where Brooks Hatlen is committing suicide you see him engraving "Brooks was here" into the wood panel near the ceiling. The table he is standing on puts his face opposite the vertical wooden bars underneath the engraving (we see this in a shot looking up at him through these bars). Then when he rocks to tip the table over to hang himself he doesn't seem to fall at all, maybe a few inches if anything, yet when we see the pan out he has fallen at least 2 feet.
Continuity mistake: When Norton prepares for his suicide you see on the desk a photograph and, a bit away, a lamp. After he has shot himself the photograph is leaning against the lamp (it was too far away in the previous shot to have fallen against it). There's also some sort of card open on his desk on some paperwork which suddenly moves onto bare desk and gets shorter. (01:57:10)
Continuity mistake: When one of the "sisters" gets beaten up by Capt. Hadley he tries to escape from his cell and holds on to the bars on the other side of the passage. From the side his right hand grabs a diagonal bar, but seen through the bars he is holding on to a vertical bar. (00:43:15)
Continuity mistake: During the scene where Andy and Red meet for the first time (baseball scene) the sun is in Red's face and so, Andy shouldn't have the sun in his face. But in fact, sometimes Andy has the sun in his face and Red doesn't anymore. Either they move very quickly between scenes or (probably) the whole scene were filmed at least two times. (00:24:00)
Continuity mistake: When the warden shoots himself, he places the gun on the middle of his neck but when we see him lying there the bullet hole is now on the left side. (This is corrected on the tenth anniversary edition. The director also confirms this change on the DVD commentary.) (01:57:00)