Arden's most famous film appearance was as lead character Guy Van Stratten in Mr. Arkadin (1955), written and directed by Orson Welles. Welles had worked with Arden on the Harry Lime radio series, produced in London, and later cast the little-known actor in Mr. Arkadin, in the central role of the investigator who uncovers Arkadin's past. Reportedly, Arden was shocked that Welles might consider him for the part and initially thought that the director's phone inquiry was a crank call. Arden's performance in Mr. Arkadin was panned by some critics : The New York Times called it "hopelessly inadequate". The credits of one the film's Spanish versions misspelled Arden's name as "Bob Harden". Another Spanish print actually credited him as "Mark Sharpe". After Mr. Arkadin did poorly at the box-office, Arden pursued his acting career, essentially in supporting parts. Although he played a few other lead roles, in films such as The Depraved (1957) or The Child and the Killer (1959), he worked mostly as a character actor, appearing in film, television and stage productions.