Continuity mistake: In the scene where Gru first meets Lucy Wilde, Gru takes out his freeze ray and fires it at Lucy. Lucy stops the freeze with a flame gun thing and then she walks over to him and tazes him. Gru then drops the freeze ray, but it disappears when she goes to put Gru in the boot of her car.
Continuity mistake: After watching El macho activate the dance floor key to the lift, Gru then does the same thing. During the first attempt, Gru spills guacamole on the floor, his nacho hat gets sliced in half and then he throws the nacho hat on the floor. Gru then fails to unlock the lift so he tries again. Only now, the nacho hat and the guacamole have vanished.
Plot hole: The rocket is launched with Gru and Lucy attached to it. All of the minions are all around them at El Macho's lair at this point, yet when they jump off the rocket several hundred miles later, three Minions appear on a boat behind them. Considering Gru and Lucy were being shot several hundred miles per hour in just a matter of seconds, there is no way the three Minions could have reached Gru and Lucy all the way from the lair in that short time.
Continuity mistake: When Gru is making balloons with his balloon gun thing he attaches an inflated unicorn balloon to the door frame and an exterior shot of the front lawn is shown. This shot shows a playhouse on the right hand side of the lawn. Later on, when Lucy arrives at the house, the playhouse is no longer on the lawn.
Continuity mistake: In the opening scene at the Arctic Circle, two of the workers are shown playing poker. The player on the right pushes the coin pile to the left side of the container. A couple of shots later, after the player on the left has claimed victory, the coin pile has suddenly moved to the middle.
Plot hole: When Gru and Lucy are searching Eduardo's restaurant, Eduardo's pet chicken begins a fight with Gru and Lucy which involves a lot of screaming, breaking tables, the chicken battering Gru which was all very loud, yet Eduardo only finds out someone was in the restaurant as soon as he walks up to the door, despite all the noise from the fight between Gru, Lucy and the chicken.
Audio problem: As Gru attempts the dance floor key, some of the guacamole from his nacho hat falls out of the hat and lands on one of the keys which then triggers one of the sound effects. An axe then chops off the rear end of his nacho hat and lands on the part of the dance floor behind him, but no sound effect is made from the floor.
Other mistake: As Eduardo goes to leave the cupcake shop, Gru believes he could be El Macho and Eduardo leaves. Gru tells Lucy about El Macho for about 90 seconds, then Eduardo is seen from outside the cake shop window only just about to go up the escalator, when the distance between the shop and escalator is only a few meters.
Continuity mistake: When Doctor Nefario is having a send off, he begins to blast off in his scooter very slowly. The shot after he says "This may take a while", the Minions begin to leave the area, yet in the next shot, the other Minions have vanished completely. There was nowhere near any time for then to have left the area that quickly.
Continuity mistake: One of the minions is shown dressed as a maid hoovering the floor. The hoover continues to move along the floor after the minion answers the door. The hoover is shown moving past the door. But when the next minion is shown, the hoover is now shown only just going past the door.