Continuity: Ann's hairstyle changes between shots during the first scene after she returns to the palace after saying goodbye to Bradley. Watch her bangs change between medium shot and close-up.
Revealing mistakes: When Joe Bradley follows Ann through the streets, people can be seen watching the filming rather than acting natural.
Continuity: After her haircut, when Ann enters the piazza, clock tower 1 reads 12:35 pm, but when Joe follows behind her, it reads 12:32 pm. When Ann sits in front of clock tower 1 in medium shot and Joe "runs into her", it reads 2:40 pm, even though it's only been a few minutes between entering, getting gelato and sitting down. Their conversation starts at 2:40 pm, but during the close-ups of Joe, clock tower 2 behind his head reads from about 4:55 pm - 4:58 pm, and when he stands up at the end of conversation and says "Today's going to be a holiday", clock tower 1 behind them in the medium shot reads 3:50 pm.
Continuity: After Joe throws his drink on Irving, a visible wet mark appears on Irving's shirt. Yet when they emerge from the bar just moments later, the wetness appears to have disappeared.
Audio/visual unsynchronized: When Anya and Joe are on the scooter, her words don't match her mouth.
Continuity: When Ann is first in Joe's apartment, he removes the "tie" from under her shirt collar and the collar stands up. In the next shot, it's again lying flat.
Continuity: When Joe is saying farewell to Princess Ann when she first leaves his apartment, he places his hand on the door handle. In the next shot, his hand is at his side and he then places it on the door handle again.
Continuity: As Anja surreptitiously speeds away from the embassy, stowed away in the back of a delivery truck, the crates that she hides behind change.
Continuity: After Ann leaves Joe's apartment, when she looks in the salon window, her tie is on and cuffs are buttoned but when she sits down in the hair salon chair, her cuffs are rolled up slightly. When she leaves the salon her cuffs are rolled up slightly, but when she approaches the gelato stand, her sleeves have been rolled up to mid-bicep. She sits down on the banister with her gelato, tie on, but a moment later, the tie is gone (and never returns) and her top blouse buttons are open. Through their tour of the Coliseum, Ann's neck is bare but on the scooter ride leaving the Coliseum a striped scarf appears mysteriously around her neck. In the car as Joe drives Ann back to the palace, both the striped scarf and tie are missing.
Continuity: When Joe and Ann are in the taxicab, the level of the window is alternately below her neck/in the middle of her face between shots.
Continuity: In Joe's apartment, when he gives the pajamas to Ann, the pajamas hang covering her left arm. In the following shots her left arm is bare around the pajamas.
Continuity: Still in Joe's apartment, when Mr. Hennessy is finishing his speech to him, Joe is holding the envelope with both hands in front of his body. In the next shot, when Mr. Hennessy leaves, Joe is holding the envelope with his right hand leaning on his hip.
Audio/visual unsynchronized: After Joe rolls Ann out of his bed onto the couch, Ann mumbles, "So happy." However, her mouth doesn't move.
Continuity: When Joe picks up Ann to move her from the couch to the bed, there is a blanket lying on the bed as he goes to pick her up, but it is hanging over the end of the bed as he walks around the bed.
Miscellaneous: When Ann is sitting on the banister in front of the clock tower, her cone has a large scoop of gelato, but when Joe arrives a moment later and sits beside her, the gelato is almost gone.
Continuity: When Anne climbs into the back of the truck to escape the palace, there is no canopy. When she later climbs out when the truck is stopped in traffic, it has a canopy.
Continuity: When we see for the first time the truck where the princess is escaping the palace, there is a Cinzano box inside. But when Anne climbs into the back of the truck the brand "Cinzano" is not seen any more and another brand appears instead.
Continuity: When the princess and Joe Bradley stand in front of the magistrate after the scooter incident, her blouse is dirty and so is her face. When they come out of the police station, her blouse is spotless and so is her face. She could conceivably have washed her face in the interim, but there would not have been an occasion in 1953 to clean and dry a blouse that quickly.
Continuity: When Princess Ann accepts her change from the Gelato salesman, she puts the change in her left pocket. Immediately afterward, when the flower salesman is trying to sell her flowers, she shows him that she has very little change left. When she does this, she takes it out of her right pocket, not her left where she had just put the money.
Continuity: After Joe returns to his apartment upon finding out from his boss that Princess Ann is sleeping there, he straightens the bed, moves the pillow, and moves Ann from the couch back to the bed. In the process of tidying his apartment, he moves his alarm clock to the center of the top of the bed's head board. In the scenes following while Ann awakes, as the camera cuts back and forth, the clock changes places back and forth from the center to the left on the head board.
Revealing mistakes: The photo Irving takes during the fight at the dance, of Ann smashing the secret service agent over the head with the guitar, is not the one taken at the moment indicated in the film and shown later as the photograph. Supposedly, when Ann first hits the agent, Irving has missed it and calls out for "Smitty" (Ann) to hit him again -- and Ann obliges, striking the agent on the head a second time as Irving shoots the picture. But a look at the subsequent photo clearly shows that it was in fact taken at the moment of the first blow, not the second. In the action, when Ann hits the agent the second time, the guitar appears already broken, and the agent is turned almost 180 degrees away from Ann's face and is already sinking down from the first blow, his face barely visible. But the photo -- supposedly the only one Irving got -- clearly is of the first, not second, blow. There, in both the live action and the photo, the agent is facing to his left and has not sunk so far down, his face is mostly visible, and the guitar is not as damaged as in the second blow. That the photo was actually taken of the first blow is further indicated by a close viewing of the live action of Ann hitting the agent the first time. At the moment of impact the film has a brief jump-cut, indicating that a frame has been deleted from the film, and in addition the tail-end of a flash from a camera's flashbulb can be seen very briefly immediately after the cut frame. The missing film frame coincides exactly with the instant Ann hits the agent with the guitar, and is the identical shot that was used as Irving's "photograph", which he later presents to Ann in the packet of pictures he'd taken. But it's a photo of the supposedly un-photographed first blow with the guitar, not of the second blow, the only photo Irving was actually seen taking.