* Peter Wyngarde would later play Jason King in the series "Department S".
* Peter Wyngarde also appears in Episode #98 "The Gadic Collection"
* Suzanne Lloyd also appears in Episode #31 "Luella", #35 "The High Fence", #44 "The Revolution Racket", #92 "Simon and Delilah" and #105 "The Time to Die"
* Michael Wynne also appears in Episodes #31 "Luella" and #70 "The Spanish Cow"
* Jeremy Young also appears in Episode #115 "The Ex-King of Diamonds"
* Edward Bishop also appears in Episode #44 "The Revolution Racket", #45 "The Saint Steps In" and #69 "The Saint Bids Diamonds"
* Edward Bishop was later a regular of the series "UFO" and also had an uncredited role in the 1971 James Bond movie "Diamonds are Forever" (latter information contributed by Bruce Vail)
* Peter Elliott also appears in Episodes #30 "The Romantic Matron" and #42 "Jeaninne"
* Steven Scott also appears in Episode #6 "The Pearls of Peace"
* As the name implies Franco de Cesarie's role strongly reminds of taxi driver Marco de Cesari played by Warren Mitchell (Episodes #2 "The Latin Touch", #12 "The Charitable Countess" and #21 "The King of the Beggars")
*
When Moore walks into the Zambetti
house notice that the background is just a painting. It also doesn't fit with the exterior scene where Franco waits for Templar in his taxi. (0:19)
*
The car in the backlot has side mirrors, while the car in the background projection does not. (0:21)
*
Note the red stairs in the background - 
in the next scene Templar chases Berreeni down the same stairs. (0:22) The red stairs can be seen several times during this episode.
* An audio introduction to this episode by Peter Wyngarde can be found on the Umbrella DVD.