The Adventure of Sherlock Holmes' Smarter Brother is a 1975 American musical comedy film with Gene Wilder, Marty Feldman, Madeline Kahn, Dom DeLuise, Roy Kinnear, and Leo McKern.

The trail leads to Gambetti, who has made a deal with criminal mastermind Professor Moriarty to sell him the document, which foreign powers have offered £50,000 to acquire.

After Smarter Brother, Wilder went on to write, direct, and star in three more features over the next ten years (The World's Greatest Lover in 1977, The Woman in Red in 1984 and Haunted Honeymoon in 1986).

[6] Vincent Canby of The New York Times called the film "a charming slapstick comedy" that like Young Frankenstein "is full of affection and generous feelings for the genre it's having fun with.

"[8] Gene Siskel of the Chicago Tribune gave the film two stars out of four, calling it "tedious" and Sigerson "a bland character at the center of a gimmick-filled movie" that "recalls the great detective only by name and occasional costume.

"[9] Charles Champlin of the Los Angeles Times declared it "a light, easy, brisk but unforced, professional, kindly and ingratiating trip through Holmes' sweet home as it never was".

[10] Gary Arnold of The Washington Post called it "an enjoyable, encouraging beginning" to Wilder's career as a writer-director that "reveals a surprisingly inventive and conscientious comic imagination at work".

"[12] John Pym of The Monthly Film Bulletin called it "better in its parts than as a whole, and essentially a showcase for the individual performances of Wilder himself, Marty Feldman, Madeline Kahn and, particularly, the perpetually energised, rubber-faced Dom DeLuise.