The study of skin disease pattern and health care activities in the Out Patient Department (OPD) of National Hospital of Dermatology and Venereology from 2009 to 2011 by used secondary data of 605,741 patients participated in the OPD. Objectives: Describe the changing of skin disease pattern by seasons, the advantages and disadvantages of services provided in the OPD. Design: cross-sectional study, retrospective and using secondary data. Descriptive analysis and chisquare test were used. Results: The number of skin disease patients is tending to increase more and more in hospital. They are divided into 14 main groups (81,6 percent). In which, most of patients belong to 6 main groups, including: allergic dermatistis (34.5 percent), acne group (13.5 percent), erythematous squamous lesions (6.4 percent), fungal infections (6,4 percent), STIs (4.3 percent) va pyoderma (3.6 percent).