Continuity: The item in Higgins' hand when celebrating Eliza's triumph at the ball.
Continuity: The recording Higgins plays of Eliza speaking in the last scene of the film is different dialog from the actual scene that was supposedly recorded.
Revealing mistakes: In almost the final scene, when Higgins goes to open the door with the key, he inserts the key, but doesn't turn it before opening the door.
Continuity: Higgins arm on the back of the chair during 'Let A Woman In Your Life'.
Crew or equipment visible: In the final scene Prof. Higgins is alone in the room, sitting in his chair, a shadow that appears to be Eliza's is visible on the floor as she approaches. It is mentioned by Gene Allen on the DVD that the shadow is actually his.
Audio/visual unsynchronized: As Eliza collects coins from the ground just before the "Wouldn't It Be Loverly" number, a man in the background standing on a cart calls out, "You're no Eastender, kid! We've got a bloomin' heiress in our midst." There's an odd extra syllable between the two lines, which explained by the subtitles (on the 1998 DVD release); these read, "Shouldn't we stand up, gentlemen? We've got a bloomin' heiress in our midst." Presumably the subtitles are based on the original script and/or dialogue track, and the first sentence was spliced out for the final release, in favor of the "You're no Eastender, kid!" line.
Anachronisms: In the number "With a Little Bit of Luck", as Alfred Doolittle walks to the left side of the screen and sings, "They're always throwing goodness at you, but with a little bit o' luck a man can duck," the camera pans far enough to the left to reveal the tracks of a modern rubber tire in the dirt, probably made by the camera dolly or a mobile light stand.
Continuity: When Higgins comes home after the Grand Ball he takes off his shoes and holds a cigar in one hand which repeatedly changes direction between shots.
Continuity: When Higgins and Eliza are on the way out to the ball, the head maid is in the line with the other maids, but in the next shot she is again going into the line.
Continuity: When Professor Higgins talks about the breakfast cakes, Colonel Pickering drinks his coffee and puts the cup back on the saucer. But in the close up shot he repeats the same action.
Continuity: When Eliza sings "I Could Have Danced All Night", she goes into the bathroom, turns on the tap, and wets a washcloth which she presses against her chin and neck. She never turns off the tap, and it is still running as she exits the bathroom. In the next shot, you see one of the maids turn off the bathroom light, but she doesn't lean over and turn off the tap.
Continuity: In the early scene where Eliza offers to pay for lessons, Higgins tells her, "Sit down!" and points across the room to a chair. He points with his right arm. In the next shot, Higgins is pointing with his left arm.
Audio/visual unsynchronized: When Eliza is singing "I Could've Danced All Night", when she is singing the last reprise of the chorus when she is in bed her lips often are moving slower than the words are being said and she is seen dragging a little bit when some of the longer notes are being held.
Crew or equipment visible: When Higgins first asks Eliza to recite the verse, "In Hartford, Hereford..." and he makes the mirror rotate, you can see the camera and the crew at times as it is reflected in the mirror.
Continuity: Eliza puts down her basket by the fire when she is singing "Wouldn't It Be Loverly". After the song is over and she leaves in the carriage, she does not have her basket.
Miscellaneous: Where Professor Higgins says, "She should be hung" that is in fact incorrect grammar - the correct term for a person is "hanged".
Continuity: When Eliza exits Mrs. Higgins' garden after singing "Without You", she goes through the gates that lead inside the adjoining room. They are left swinging behind her. When the camera turns to Higgins immediately after, the gates are perfectly stationary. There was not enough time for the gates to stop swinging in the small amount of time between the two shots.
Revealing mistakes: During "The Rain in Spain", you can hear Audrey Hepburn's voice mixed with Marni Nixon's voice. It's especially obvious the first time she properly sings, "The rain in Spain stays mainly in the plain," after Higgins' line, "I think she's got it, I think she's got it."
Miscellaneous: When Prof. Higgins sings "Never Let A Woman In Your Life" he turns on several phonographs, seconds later he turns off one of them but all of the sounds stop.
Continuity: During the opening scenes at Covent Opera House there is a woman wearing a long purple dress. She is shown getting into a car, and then seconds later is seen running when the rain starts.
Factual errors:Charles E. Fredericks looks nothing like King George V did in real life. (This could have been intentional, as the King in the scene may have been a character that Eliza dreamed a King would look like, being a flower girl, she may not have taken much heed to current politics or what the king would have looked or dressed like in the palace. Or, she could have been dreaming the same may many girls do, imagining a King to look like Henry VIII, the most common imagination of a king.)
Continuity: When Eliza is singing "I Could Have Danced All Night," the maids are furiously trying to dress her into the nightgown. Her right sleeve is tied but the left remains untied until she exits the bathroom where it's tied.
Continuity: When Eliza is singing, "Show Me" to Freddy in the alley, Freddy trips over a dustbin, knocking it down and releasing a large sheet of paper that falls to the middle of the alley. As they go back through the same alley towards a taxi, the paper and dustbin are gone.
Factual errors: Ascot racecourse runs clockwise, therefore if the member's lawn is on the main Grandstand/flat area, the horses running past in the Ascot scene should have been running the other way - left to right, not right to left as seen in the film. (However, if the crowd is in fact on the infield - unlikely because tradition is that is where the poor man could watch - than this cannot be viewed as a 'factual error'.)
Continuity: In the final scene when Henry Higgins sits on the chair as he listens to her voice on the phonograph, Eliza's shadow can be clearly seen on the carpet behind him, to his left (screen right). In the next shot she is is shown entering the room.
Errors made by characters (possibly deliberate errors by the filmmakers): When Alfred sings "Get Me To The Church On Time", he sings "Stamp me and mail me", which is an American term, rather than the British term "Stamp me and post me".