Continuity: Lorelei has slender hands with long fingers and her nails are manicured. But, when she pulls the roll of film out of Ernie's pants, her hand is short with thick fingers and her nails are cut.
Continuity: Lorelei's hair in her "Diamonds are a Girl's Best Friend" number is straight. But when she is backstage, minutes after having finished, her hair is curly.
Errors made by characters (possibly deliberate errors by the filmmakers): In the courtroom, Malone introduces Piggy as Sir Francis Beekman. Minutes later, the judge addresses Piggy as Lord Beekman. As Piggy holds a knighthood, not a peerage, he would never be addressed as anything other than "Sir".
Audio/visual unsynchronized: In the scene where Lorelei is seeing Mr Esmond off at the ship, the words "Bye, lover!" are heard but Lorelei's lips do not move.
Continuity: When Loreli and Dorothy are in New York, it is announced that the ship is bound for Cherbourg. Yet, when they dock, they are in Paris which can't accommodate large ocean liners.