Continuity mistake: When Gene Kelly and Donald O'Conner stop for car trouble, a trolley goes by. After Gene gets bombarded by fans and runs away, he runs after another trolley going by and jumps on. The same people are in the trolley each time. (00:14:50)
Continuity mistake: In the scene where Bing Crosby is talking to Ethel Barrymore at a picnic day for the girls of he very snobbish school, he makes a big deal out of taking out a cigarette and lighting it, but in the next shot - no cigarette.
Continuity mistake: When Jack is speaking to Princess Eloise near the water well, he turns his head to the right. In the following shot, his head is turned to the left.