"Our Last Summer," includes the lyric "that was the time of the flower power," which is usually a reference to the late 1960s. In the same scene, Harry says he traded his John Lydon tee-shirt to get a guitar for Donna. Lydon was a member of The Sex Pistols, which formed in 1975.
ABBA's iconic lyric "My my, at Waterloo, Napoleon did surrender," is incorrect. Napoléon Bonaparte retreated from Waterloo in June 1815, attempted to hold his army together for a month, then traveled to the European coast, where he surrendered to the British Navy.
During "Take A Chance On Me", Bill appears to be standing directly under Rosie as she falls from the roof since he's looking directly above him. When Bill actually catches her it's clear that she is coming from the right side of the screen.
As "Lay your Love on Me" transforms into Sophie's bachelorette party, cast members hold Sophie up and she drinks from a bottle, then throws it. After she throws it, they lay her on her back and her hair falls off her shoulders. In the following close-up shot, her hair falls off her shoulders again.
After telling her guests about the toilet, Donna goes to open the window shutter - which then falls off - with just her left hand. When the camera switches to the outside shot, Donna opens the shutters with both hands.
At the chapel, Sam has just proposed to Donna. She says she's not a bigamist. Sam says neither is he and that he has loved Donna for the past 21 years. To his right stands Sophie, who after hearing Sam say this, is all choked up and looks like she's about to burst into tears of joy. Immediately after you see this expression we see Donna very briefly (one or two seconds). When the shot goes back onto Sam and Sophie, Sophie has a huge grin on her face. Nothing is said by Donna or Sam in this extremely brief period of time that would justify her instantaneous change of expression.
When Sophie is finally dressed for her wedding, the gauzey material is predominately over her right shoulder/breast. Next shot it is over her left. When she gets on the donkey, it is completely off her right side and her bra shows.
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.
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.
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.
In the Super Trouper scene, when we see Donna, Tanya and Rosie raising their left hands, we see that Rosie is just behind Donna's sleeve. However, in the next shot, in which we only see Donna, we can't see Rosie or her shadow at all.
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.
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.
When Tanya is singing "Does Your Mother Know", she walks away from the bar and goes out to the beach to join the crowd of men who are dancing. As she's walking, there's a side shot of her, and in the background you see an extra with a towel around her waist wearing red wayfarer sunglasses. But then there's a face-on shot of Tanya, and the extra's sunglasses have disappeared.
When Meryl Streep closes the bedroom door in the scene right before "Dancing Queen", you see Julie Walters' reflection in the mirror next to her, hands on her hips. In the next shot Streep turns to face Walthers, who now suddenly hasn't got her hands on her hips anymore.
Donna, Tanya and Rosie are singing Super Trouper for Sophie's Hen Party - when they get to the end of the song and all 3 ladies put their hands one of top of each other (whilst they are singing 'Like I always do') and then lift them above their heads. Rosie's hand has changed, in the first shot it is her right and in the second her left hand.
During "The Winner Takes It All," you first see the cliff with the church and the sun very low on the horizon. Later during the scene, the sun is much further to the right and higher in the sky (the sun glare on the water is bright white). The scene was apparently filmed in the morning (and not in the evening) and we see a sunrise and not a sunset.
During "Dancing Queen", Donna hides her face in the pillow while looking at Rosie and Tanya singing. On the right side of the bed where Donna is lying is a red table lamp, a glass cup and some stuff on the table. During the chorus, Donna jumps on the bed, and in the jumping shot, the table lamp and everything else on the table is covered with a white cloth with a red pattern.
When Donna is fixing the crack in the tiles, the tip of the filler-gun breaks off. She stands up, and a bit later waves the filler gun, with the tip back on. The pistol has been out of sight (her hands down) during the scene, but she didn't look down once, and we see that she is carrying a bowl in the other hand, so she would not have had a chance to put the tip back on again.
When Sophie is hurrying all three potential fathers into the goathouse, Sam is the last one in. As he walks in we see his bag strap slide down from his shoulder to his elbow. As the shot changes, the strap is now instantly back up on his shoulder.
When Sky hands Tanya and Rosie a drink when they first arrive on the island and meet him on the courtyard, Tanya raises her glass and begins to drink. Then when the shot changes her hand is back down by her waist.
Just as Donna starts singing the last of 'Slipping Through My Fingers' Sophie is put on a donkey to be taken up to the hall for her wedding. Donna and Sam are left alone and Donna sings "The Winner Takes it All' but when she gets up to the hall the donkey is nowhere to be seen.
When Sophie is in her bedroom with Ali and Lisa after they have just arrived, Ali has a scarf and she places it on her shoulders. In the very next shot it it now suddenly wrapped around her shoulder, even though she didn't have time to wrap it around.
When Donna climbs on top of the goathouse after seeing Sam, Bill and Harry, and begins to sing "Mamma Mia", as she rolls around all over the roof her dunagrees (especially the knees) become dirty. However the amount, prominence and position of the dust and dirt on her clothing changes a few times during the whole scene.
When Sky is getting his hat and cigar as "props" for his stag party, as he leaves the room wearing the hat and holding the cigar. In the second shot as he walks past Sophie, there is a long loose cord hanging down from the brim of the hat - which wasn't there in the first shot.
By the end of the song "Chiquitita", Donna has a red rose in the side of her head (positioned in her hair) after Rosie put it in there. As the shots differ, in some shots the red rose, which should be visible (judged by the amount of the side of Donna's head we can see), is not there. It appears and then disappears a few times and is not due to the angle.
When Tanya and Rosie are talking to Donna in the bedroom just before the "Dancing Queen" number, they are talking about how bad Donna used to be. Rosie then puts a hat on Donna and Tanya puts a green feather boa on Donna's shoulders - twice - between shots.
When Donna, Tanya and Rosie are on the couch talking, Tanya asks Donna "if she's getting any." As she asks her this, the shot switches angles. And as it does, the towel that Tanya is wearing on her head changes from dangling behind her shoulder to suddenly hanging in front of it.
During one song, an extra is up a ladder, which is pulled out from underneath him, leaving him hanging from the window ledge. In the close-up, a safety wire is visible, going out of his clothes and up into the window.
When Sam, Bill, and Harry first arrive at the Villa, they all seem known about Donna's daughter. Later, before "Dancing Queen," Donna says she never told any of the men about Sophie. We can assume that Sophie's name was on the invitations.
The goof items below may give away important plot points.
When Donna kisses Sam after she says "I do," she has a broad ring on her right pinky, and two rings on her left hand (middle and ring finger). In the very next shot the ring on her left ring finger has switched onto her right ring finger. Also, her right hand changes position between the two shots.
When Sam is singing "When All Is Said and Done" to Donna, he starts out with his sports-coat on and you see the end of the coat sleeve when he reaches to caress Donna 's face. However when the camera shows him singing, he is only wearing his dress shirt and his cuffs are rolled up. Since the entire scene setting has changed between the shots as well - with Donna having her shawl now over her shoulders, and all the people previously standing around now sitting down - one can assume that these are actually two separate scenes, and the intro of the song just being laid over the end of the marriage scene.