Continuity mistake: Soon after arriving, Tanya and Rosie are at a bar and suddenly Donna comes out in tears. Tanya is just receiving a cocktail from Pepper, the bartender. Rosie and Tanya then hurry after Donna - and during the rest of this scene, the amount of drink in Tanya's cocktail keeps lowering then rising.
Continuity mistake: During "Money, Money, Money" Donna walks into the kitchen and all the staff are sitting at the table. They hurriedly get up and start working, and a newspaper is left right beside the large fish on the table. When the shot goes back with the table visible, the newspaper has gone.
Continuity mistake: During the wedding scene, all three of Sophie's possible fathers stand up and gather behind her on the aisle. In one closeup shot Sophie turns around to say something to Sam - in this shot the right part of her hair is behind her right shoulder. In the next shot as she is turning around back to face the priest, her hair is suddenly neatly in front of her right shoulder.
Continuity mistake: When Tanya and Rosie arrive at the island, they get off the boat and walk up the pier. They break into song with Donna (who is walking towards them) but as the shot keeps changing, the two old men standing on the pier disappear and re-appear every time the camera changes.
Continuity mistake: During the last half of the movie Donna wears a red sweeping shawl over her shoulders, with her outfit for Sophie's wedding. Many times the position of the shawl is not consistent during shots - most noticeable after she walks Sophie down the aisle, then sits down.
Audio problem: Sophie and her boyfriend sing at the beach, he says he likes to smoke and pronounces the word "true" with the camera facing him. Right afterwards there's a side shot and music is heard with no lyrics, but he is mouthing as if singing. Then back to a front shot and now he sings and mouths.