A retrospective study on 72 dogs with demodicosis, presented to Veterinary Teaching Hospital of Chonnam National University between 1987 and 1996, is reported. About 18% of the dogs with skin disease had demodicosis. About 75% of the patients with demodicosis were purebred dogs, and the short-haired breeds had a much higher incidence than do long-haired breeds. The age of the patient ranged from 1 month to 3 years, and about 63% of the patients were less than a year of age. Sex and seasons have been shown to have no effect on the development of demodicosis. A hereditary predisposition of generalized demodicosis has been observed from an affected litter.