The series was remarkable for pairing an American character, Napoleon Solo, with the Russian Kuryakin as two spies who work together for an international espionage organization at the height of the Cold War.

When an acute reaction to penicillin hospitalized him in the early days of filming the series, McCallum took the opportunity to give serious thought to how he might flesh out what was, at that stage, a sketchy peripheral character.

The approach he hit upon was to build a persona based on ambiguity and enigma, hiding, rather than revealing, aspects of the character's background and personality.

"[3] Kuryakin is consistently referred to as Russian; however, he appears to have spent at least some of his childhood in Kyiv, Ukraine ("The Foxes and Hounds Affair").

Kuryakin also inspired the surname and character of Simon Illyan in Lois McMaster Bujold's Vorkosigan Saga science fiction series.

In the NCIS season 2, episode 13 "The Meat Puzzle", Kate Todd asks Special Agent Gibbs "What did Ducky look like when he was younger?"

Kuryakin was the youngest man to ever join the KGB Special Forces, becoming one of their best "within three years," which was a way to deal with the shame his family was left in.