Prior to the start of production, filmmakers met with the U.S. Treasury Department over the legality of depicting real money in counterfeiting scenes; once government approval was obtained, they arranged to borrow $313,000 in $100 bills from the Bank of America, for a daily interest fee and $5,000 in insurance. The money was allowed to be shown in the film but not in the trailers advertising it. The borrowed cash was delivered to the set daily by a Brinks armored truck, and guarded by four security guards.
The directorial debut of Howard Morris, best remembered for his role as Ernest T. Bass on The Andy Griffith Show (1960).
Co-stars Milton Berle and Dorothy Provine had four years earlier played husband and wife J. Russell Finch and Emeline Marcus-Finch in It's a Mad Mad Mad Mad World (1963).
Erin Moran's debut.
Even though his character is middle-aged or older, Victor Buono at 28 was the youngest member of the principal cast.