The champagne that George Brower stocks his refrigerator with is the exact same brand that the murderer from the previous episode, Columbo: Columbo and the Murder of a Rock Star (1991) stocked his refrigerators with.
Columbo reveals that he and his wife's silver wedding anniversary is coming up very soon, meaning they were married two years prior to Prescription: Murder (1968).
This is the third episode in which Columbo speaks fluent Italian.
The broken face of the victim's watch was used to establish a false time of death,
and had happened 18 years earlier, in Columbo: Candidate for Crime.
This episode has an unusually long time dedicated to the setup. Columbo does not appear until 32 and half minutes into the runtime.