At the start, Michael Caine's character's hair would change from his natural wavy style to permed, particularly between the scene when his character dined just before going to the beach to arriving at the beach.
While driving, the vacationers encounter a procession en route to a wedding on the beach. The same set of cars forming the procession is seen to pass them twice.
While shaving, Matthew nicks his cheek and it is bleeding. The cut appears in the next scene which takes place just a few minutes later, but in the scene that takes place later on that day, the cut has disappeared completely.
The beach scene in which Matthew Hollis (Michael Caine) and Victor Lyons (Joseph Bologna) see several topless women (including their daughters) is Ipanema Beach. Not only is Ipanema Beach not a topless beach, topless sunbathing is not permitted on the city beaches of Rio de Janeiro.
When Nikki goes hang-gliding, she walks up to the glider, grabs the bar, and runs towards the cliff. In the next shot, as the glider flies off, she is properly strapped in.
In Rio, two musicians are playing in the streets before the four protagonists are seen driving a car on the way to the rented house. One of the street musicians (the one with the guitar) looks directly at the camera not once, not twice, but three times in less than 10 seconds.
When Victor and Matthew are fighting in the bedroom, some of their lines were dubbed in later. The most notable is Matthew's line, "Those are my balls," because when he says it, his mouth does not move.