Continuity: In the scene where Marty is being chased by the Libyans, a few times they cut away to show the instrumentation in the car. The first time the odometer reads 33064.2 and the trip counter says 88.8; the second time it's goes back a little to 33061.8 and 86.4. A few seconds later we see it as he turns the corner, and it goes down again from 33,061.8 to 32,994.4, the trip counter has gone from 86.4 to 19!

Continuity: When Marty is writing the letter to Doc before he goes into the future, the word "disaster" is the only word in the last line. Yet when Doc shows Marty the letter when it has been all taped up, "terrible disaster" is the last line. Also, the handwritring in each letter is different (i.e. Marty's signature). They are two different letters.

Continuity: When Doc and Marty are at the Twin Pines Mall and Doc is telling Marty about the car etc, he says "never mind that now, never mind that now..." and Marty has the camera facing the ground, yet later when Doc in 1955 is watching the video, you can see him saying that on the video.

Continuity: When Marty is standing over his father's bed in 1955 persuading him to date Lorraine, there is a hair-dryer in Marty's belt that appears and reappears between different frames. Really obvious. [This scene was originally longer, including a part where Marty removed the hair dryer from his belt. Still a mistake, but there's the explanation. Some people keep bringing up another deleted scene where Doc finds a hair dryer, which has nothing to do with this. The mistake is the disappearing hair dryer in this specific scene - whether we see it again or not elsewhere is irrelevant].

Revealing: At the end, the DeLorean hits the left dustbin and comes to a halt - you can easily see that it's not Christopher Lloyd driving, it's someone with a much bigger build, wearing an awful white wig.

Continuity: In the Cafe of 1955 Marty goes into the phone booth to look up docs name in the phone book, when he finds it the name is on the left hand page yet when he tears it out of the book he tears out the right hand page. One could say he turned the page to tear it right-handed, however when he is asking the waiter if he knew where the address was, he is reading the address on the same side he tore out - check the tears on the edge.

Factual error: When Bif is chasing Marty (on the skateboard) around the Town Square, you can see sidewalk handicap ramps at the corners. Those didn't come into being until the 70's.

Factual error: The electric guitar Marty plays at the "Enchantment Under the Sea Dance" is a Gibson ES335 (or 345 or 355). This guitar model debuted between 1957 and 1958 yet he's supposedly playing it in 1955. It would have been more accurate to have him using a Fender Telecaster (1950) or Stratocaster (1954). The Gibson 335 was not made until 1958.

Continuity: When Marty is trying to escape from the van he turns the time circuits on. However, the time circuits were already on - you can see them illuminated when he first puts the car in gear.

Continuity: When Marty runs out of the cafe in 1955 being chased by Biff, he runs up to the two boys and lifts one off his scooter thing. As he does this the other boy is trying to stop Marty form taking it, but as the camera changes the other boy is just standing still on his scooter.

Continuity: When Marty is in 1955, he is in shock and walking on the pavement when a car comes by. On the first shot when it comes towards him it has two speakers, on the second shot when it's moving away, it only has one. On the second shot of the car with only one speaker, the A-frame sign is also turned the other way.

Continuity: After the scene where Marty and his band are rejected from the school tryouts, Jennifer and Marty are sitting down and a lady comes by and asks them for change to save the clock tower. After they attempt a kiss, Jennifer's dad calls for her from the car. In the background, an African-American man is standing looking in the window of a building, and then walking right. In the next shot, he has moved all the way to the left and is walking right.

Continuity: When Martly finishes his rambunctious guitar solo at the dance the camera pans the crowd. In the distance on the left we see Mr Strickland uncovering his ears. After this they show a close up of him uncovering his ears again.

Continuity: When Marty's coming home at the beginning of the film, he's watching the discussion between his father and Biff who complains about the wrecked car and his reports. In the two shots which show Marty, there's a glass full of candies near to him. When Biff steps to the glass and lifts the lid, half of the candies are gone.

Visible crew/equipment: At the end of BTTF they all pile into the DeLorean which reverses up to the camera where the matte box and what looks like the top of the cinematographer's head are reflected in the chrome number plate.