Continuity mistake: Before Edward is looking at the family pictures you can see some scars on his face are open, when the camera focuses back on him the scars are closed.
Continuity mistake: When Officer Allen is talking to the psychologist, he begins to raise his hands towards his head right before he says "But will he be all right?" but in the next shot his hands are down by his side.
Continuity mistake: In the scene where Edward is giving dogs haircuts, we see he has a table, the table switches between one and two tables between shots. When we see a diagonal view of Edward's face, the table is in two, otherwise, it's one table.
Continuity mistake: When Edward pushes Jim out the window, he stabs him in the stomach first. When Jim is backing toward the window, we can see a rip in his shirt where he was stabbed, but when his body is on the ground, there is no rip and the blood is much higher than where he was stabbed.
Continuity mistake: Edward stabs Jim and crashes him through the large attic window. Eight smaller window sections remain at the top of the opening, two rows of four small windows. All the outside shots (looking up at Edward and Kim) show the two lower left windows broken out, from the inside all eight windows are intact.
Continuity mistake: All thoughout the movie, the scars on Edward's face keep moving and changing sizes and depth.
Continuity mistake: Many of the bush sculptures that Edward creates in the neighborhood are significantly taller than the original shrubberies.