One-hundred-eleven herpes simplex viruses(HSV) were isolated from l09 patients who had visited the Department of Dermatology, Ophthalmology, and Gynecology of Hanyang University Hospital from 1986 through 1988, for suspected HSV lesions. The cultured viruses were classified into HSV-1 and HSV-2 by using direct and indirect immunofluorescent staining with monoclonal antibodies against HSV. In this study, HSV type 1 were predominantly involved in the HSV lesions above the waist of the patients(83.6%), and the infections caused by HSV type 2(I3.1 %) and bath HSV types(3.3%) were also noted. In contrast, the main organism of the HSV lesions below the waist were HSV-2(80.0%), and HSV-1(16.0% ) and both types(4.0%) were also involved in. The result suggested that the number of patients with HSV 1 genital herpes and/or with non-genital herpes by HSV-2 were apparently increasing. In conclusion, it is conceivable that the classification of HSV isolates might be useful for determining prognosis as well as performing epidemiologic studies of HSV infections. (Kor J Dermatol 28(2): 187 193, 1990)