Private Eyes revolves the characters in a private detective agency headed by Wong Yuk-See (Michael Hui) with two employees, a stuttered, easily bullied Pighead (Ricky Hui) and secretary/receptionist, Jacky (Angie Chiu). The agency was soon joined by an out-of-work bottling plant employee Lee Kwok-Kit (Sam Hui). Among them, they took on various cases, mostly involving adulterous men and women. Comedic adventures occurred when Wong and Lee carried out these investigations. In the movie's finale, the two were trying to capture a blackmailer to a local theater and it ties several earlier sketches together.