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.

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.

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: 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 Lorraine gets George's book out of the package, she has a bracelet on her right arm. When she hands the book to Marty, it is gone.

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.

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: 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: After Doc accidentally unplugs the cable and is sending Marty back, he unplugs the cable 15 seconds later and it shows Doc, and the clock's hand change. A split second later the clock's hand changes again.

Continuity: When Marty is standing over his father's bed in 1955, Marty puts the headphones on George and then puts the tape in the cassette player. If you notice the hairdryer is on the left side of the belt and is touching his left arm but when they cut to Marty holding the tape player out in from of him the hairdryer is on the right side.

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: At the Twin Pines mall during the chase scene with the Libyans, there is one shot were you get a great look at the driver as he's trying to start the engine. Later on you get another look at the driver as the van is moving and it's a totally different person.

Continuity: In 1955, when Doctor Brown is watching the video of himself, he sees himself saying that the Libyans are coming. You can hear a significant pause between "They found me" and "I don't know how but they found me." But in the beginning of the film he says the entire phrase without any pauses.

Revealing: When the De Lorean is struck by lightning near the end of the film, if you look closely, you can see that there is no one in the car. You may have to look closely, but you don't need to zoom in to see it. Also, since they never re-shot this scene, you can see it in all three Back to the Future films.

Other: Beginning of film. Twin Pines Mall. When Marty escapes the Libyans at the Twin Pines Mall, hits 88mph and ends up in Old Man Peabody's barn, note how the car drives in through a large opening in the barn before crashing, however, the cut to the inside of the barn shows no form of entry other than the closed doors the family are entering. In addition the inside of the barn is very small compared to the outside view.