Kjeld's brown jacket was Poul Bundgaard's own. He had bought it on Mallorca, but never wore it at home because his wife did not like it. He continued to wear it in all following Olsen Gang films.
The scene when Egon leaves his accomplices on the stolen piano truck is the only one in all Olsenbanden movies when you can see him drive a vehicle. Usually Benny was the gang's driver.
Egon, Benny and Kjeld was originally called Eigil, Sofus and Tykke-Kjeld.
The name "Egon Olsen" for the main character was a casual idea of Henning Bahs's son when his father told him that he was writing a script about gangsters.