Trivia

Despite misgivings about the poor quality of the script, several of the cast members were still enticed to appear in the film due to the prospect of spending three months filming in scenic parts of Greece. As Roger Moore put it, "Even if the film turned out to be a flop, I still got to spend several weeks with my family enjoying the glorious Greek sunshine in the splendid company of David Niven and nights on the town with Telly Savalas".

To initially establish Roger Moore's German character as being unaligned with the S.S., when the Nazi officers give him the Heil Hitler stiffed-armed salute, Moore returns it with a regular military salute.

Paul Picerni, Zeno's man, was a WWII combat veteran. He was a bombardier in a B-24 that operated over Burma. He bombed the real Bridge over the River Kwai.

The gun battle fought between Greek resistance forces and Major Volkmann's SS Troops was filmed on Rhodes in what is now sometimes called the "Square of the Jewish Martyrs". The Germans deported almost all of Rhodes's remaining Jews in July of 1944, following Britain's disastrous failure to liberate the German-held Dodecanese Islands. The events of the film occurred afterwards, as established by the mention of V-2 rocket attacks against London, which the Germans began in September, 1944. A monument to the Jews of Rhodes was dedicated in the square in 2002.

The opening scene show the Tsambika Monastery perched on a hill about 300 meters high with stunning views over the area of Kolymbia to the north. The second monastery on the side of a mountain is the Simonopetra Monastery, also Monastery of Simonos Petra, is an Eastern Orthodox monastery in the monastic state of Mount Athos in Greece. Simonopetra ranks thirteenth in the hierarchy of the Athonite monasteries. The monastery is located in the southern coast of the Athos peninsula, between the Athonite port of Dafni and Osiou Grigoriou monastery.

William Holden: As a cigar-smoking prisoner of war. Elliott Gould walks by Holden and asks him, "Are you still here?" This P.O.W. bit was an in-joke reference to Holden's starring role in Stalag 17 (1953). Holden was in a relationship at the time with Stefanie Powers, who appeared in this movie.