Appearing in this film are no fewer than twenty performers who appeared in at least one of the Sherlock Holmes movies with Basil Rathbone and Nigel Bruce, the latter playing Ramsbottom.
Robert Donat, Laurence Olivier and Richard Greene were also considered for the role of Clive Briggs.
Clive (né Vivian) James chose his name from this character.
The title comes from the famous line in William Shakespeare's "Hamlet," Act I, Scene III: "This above all, to thine own self be true."
"Lux Radio Theater" broadcast a 60-minute radio adaptation of the movie on
September 14, 1942, with Tyrone Power reprising his film role.