Objective:To clarify patterns of skin diseases among outpatients at first and return visits to Hospital of Dermatology of Chinese Academy of Medical Sciences in 2019.Methods:Data were collected from the outpatient electronic medical record information system in Hospital of Dermatology of Chinese Academy of Medical Sciences from January 1st to December 31st, 2019, and patterns of skin diseases among outpatients at first and return visits were analyzed retrospectively.Results:The total number of outpatient consultations was 1 440 580 in 2019, including 941 755 (65.37%) first visits and 498 825 (34.63%) return visits, and the daily average number of outpatient consultations was 4 332. The top 10 most prevalent skin diseases were eczema, acne, urticaria, psoriasis, seborrheic dermatitis, vitiligo, neurodermatitis, pigmented nevus, tinea pedis and onychomycosis among outpatients at the first visits, with the number of outpatient visits being 739 175 and accounting for 78.49% of the total first visits; the top 10 most prevalent skin diseases among outpatients at the return visits were eczema, acne, psoriasis, urticaria, vitiligo, seborrheic dermatitis, neurodermatitis, pigmented nevus, keloid and rosacea, with the number of outpatient visits being 399 594 and accounting for 80.11% of the total return visits.Conclusion:In 2019, skin diseases predominated by common diseases, such as eczema and acne, among outpatients at Hospital of Dermatology of Chinese Academy of Medical Sciences.