The movie begins with the Jönsson gang making a minor burglary. It goes wrong and the gang leader, Sickan, gets caught. After he has spent 10 months in jail, Vanheden and Rocky come to welcome him when he's released. But he doesn't take notice of them, and he's picked up by the mysterious banker Wall-Enberg Jr. instead. He wants Sickan to perform a burglary in Switzerland, in order to retrieve the famous Bedford Diamonds. Sickan does this but is fooled by Wall-Enberg and nearly gets caught. When he returns to Sweden and re-unites with his old gang members, he's set on revenge, both physically and psychologically...
Unfortunately the movie Varning för Jönssonligan is not yet available on Disney Plus.
| Camera | Roland Sterner | Director of Photography |
| Writing | Rolf Börjlind | Screenplay |
| Costume & Make-Up | Brigitte Reiss-Andersen | Makeup Department Head |
| Production | Lennart Norbäck | Production Manager |
| Directing | Jonas Cornell | Director |
| Sound | Ragnar Grippe | Original Music Composer |
| Art | Mona Theresia Forsén | Production Design |
| Production | Ingemar Ejve | Producer |
| Costume & Make-Up | Mona Theresia Forsén | Costume Design |
| Editing | Solveig Nordlund | Editor |
| Directing | Maria Fägerwall | Script Supervisor |
| Writing | Gösta Ekman | Writer |
| Writing | Henning Bahs | Characters |
| Writing | Erik Balling | Characters |
