Continuity mistake: When Lady enters the bedroom where the baby is put asleep, the wall in the back is an absolute chaos: A wooden chest appears/ disappears randomly; the things on the chest magically disappear only to become a blanket in the final shot; the mirror becomes a painting, and, last but not least, the wall has either a smooth paint or a wallpaper with flower motifs.
Continuity mistake: After the crocodile scene, Lady and Trump jump away and land on a narrow street inches away from the hyena cage. After the hyena stops laughing, the place is completely different: Wide and with a fountain in the middle. Lady is sitting still so they couldn't have gone somewhere else in between shots.
Continuity mistake: From left to right, in the room where Tramp chases the rat there's a chest, a couch, a huge window with fallen curtains on a table. When the rat is killed the window disappears, and thus the curtains over the table. After aunt Sarah locks Tramp, the window reappears and the curtains are back on the table.
Continuity mistake: After Tramp gets his breakfast bone from Tony's Restaurant, he carries it behind a wooden fence and starts chewing. Pretty soon a horse drawn dog pound wagon rolls by, and a worker gets out to nail an impound notice four boards away from him. But when Tramp walks over to read what the notice has to say, it's now nailed six boards from where he was just a moment ago. (00:16:40)