PROBLEM TO BE SOLVED : To provide methods for treating rosacea resulting in safe, swifter and long term amelioration. SOLUTION : Disclosed herein is a method for treating inflammatory lesion of rosacea comprising topically administering a pharmaceutical composition comprising 0.5 wt.% to 1.5 wt.% ivermectin and a pharmaceutically acceptable carrier to a skin area affected by inflammatory lesion of rosacea once a day, where as early as 2 weeks after the initial topical administration of the pharmaceutical composition, a significant reduction in inflammatory lesion was observed, and the median time to the first relapse is about 110 days or more. SELECTED DRAWING : None COPYRIGHT : (C)2019, JPO&INPIT