As Rudolf Hess, 77-year-old Sir Laurence Olivier was in poor health during filming, and required a nurse to accompany him during production. Olivier was also beginning to suffer with memory problems, and labored for hours on his one long speech, because of having trouble remembering the dialogue.
Richard Burton was set to play his character from The Wild Geese (1978), Allen Faulkner, but died a few days before filming began. Edward Fox stepped in to play Alex Faulkner, the brother of the character played by Burton.
After Richard Burton died, producer Euan Lloyd had to re-cast his part. Lloyd contacted Edward Fox, who was in the country working on his house. Fox agreed to do the movie, so he could add another wing onto his house.
After the success of The Wild Geese (1978), author Daniel Carney was asked by producer Euan Lloyd to write a sequel. Carney originally refused, as he could not think up a storyline, until Lloyd gave him one, this film's concept, the kidnapping of Rudolph Hess from Spandau Prison.
According to Ingrid Pitt's personal website, Pitt, who did not have any scenes in this film, with acting legend Sir Laurence Olivier, did however have dinner with him during the shoot, saying that Olivier was "very old, and frail by this time, but very gallant."
The film's script had been written with Richard Burton in mind for his character. Due to the death of Burton so close to the start of principal photography, Burton's part could not be re-written, except for the change of the character's name, and as such, Edward Fox had to speak dialogue, which had been written for Burton.
No characters from the original The Wild Geese (1978) movie appear in this sequel. Ironically, the film's trailer states "The Wild Geese are back!" and "This time the Wild Geese are flying higher than ever before and further than ever before!". Moreover, one of the film's taglines states, "They fly again...".
Wild Geese 1 and 2 have some relations with the James Bond universe. Roger Moore played the role of James Bond in seven movies (1973-1985). Peter R. Hunt, who directed this film, worked as an editor in the first five Bond movies (1962-1967), and then directed Bond movie On Her Majesty's Secret Service (1969). Edward Fox and Barbara Carrera have worked together in the Bond movie Never Say Never Again (1983). Richard Harris' brother's wife's next husband was Pierce Brosnan, who played Bond in four movies (1995-2002).
Last film to use the location of the Spandau prison in West-Berlin. The Spandau prison was operated after World War II by the Four-Power Authorities to house the Nazi war criminals sentenced to imprisonment at the Nuremberg Trials. It was completely demolished after the last prisoner Rudolf Hess (played by Laurence Olivier) died in 1987, to prevent it from becoming a neo-Nazi shrine.
Cast members Edward Fox and Barbara Carrera around a couple of years earlier had previously worked together on the unofficial James Bond movie 'Never Say Never Again' (1983) where they had portrayed the characters of M and Bond Girl Fatima Blush respectively.
Lewis Collins has said that he was originally hired to play Haddad, due to a contract with Euan Lloyd. Collins had headlined The Final Option (1982). However, the part was cast with Scott Glenn. Collins ironically had starred in "The Wild Geese" rip-off movie "Code Name: Wild Geese" (Geheimcode Wildgänse (1984)) which may have been a factor in his non-inclusion in this sequel.