Oral finasteride(Propecia), lmgjday, has been widely used as an effective treatment for male androgenetic alopecia since it had been approved by the Food and Drug Administration(FDA) of U.S. in December 1997. Gynecomastia has been one of the most common adverse effects in the patients who were taking 5mg of oral finasteride(Proscar), Recently, several cases of unilateral or bilateral finasteride induced gynecomastia have also been reported in 1mg of oral fmasteride(Propecia). We report two cases of finasteride(Propecia) induced painful bilateral gynecomastia, which are the first published documentations in Korea. (Korean J Dermatol 2003;41(2) : 232-234)