Just before Egon Olsen escapes from the TV studio in the beginning of the film, he tries several doors to find the toilet. Behind one of the doors he sees two old men sitting by a table in front of each other, typewriting. They are Henning Bahs and Erik Balling, the two men behind all 14 Olsenbanden films.
Actor Poul Bundgaard died about halfway during the making of the film, shortly before the interior scenes were completed. As it had been a long-time wish of Bundgaard to make this film, and his family gave their support as well, it was quickly decided to continue filming. Stand-ins were used to finish the film. At first, a lookalike of Bundgaard was cast, but as the man was not a professional actor, screen tests were not satisfactory. In the end, comedian and actor Tommy Kenter was dressed and made up to look like Bundgaard and did the bodywork, and singer and actor Kurt Ravn supplied the voice. That is why Kjeld is not shown clearly in any of the outdoor scenes. The end of the film was also rewritten.
The costumes had to be remade for all three leading actors, as both Morten Grunwald and Ove Sprogøe had gained weight over the years, while, on the other hand, Poul Bundgaard had lost a lot of weight due to his illness. So Egon's suit and hat were new, Benny got a new jacket as well (for which costume designer Lotte Dandanell had to travel to London to find a fabric which resembled the old jacket). Kjeld's jacket was the old one, but shortened in the back.
A very special problem for costume designer Lotte Dandanell were Benny's iconic yellow socks. Dandanell neither found them anywhere on sale nor had success with dying some white socks. At the end, a stocking factory in Jutland made 20 pairs of yellow socks especially for the film.