: The COVID-19 pandemic has a considerable influence on public health, either directly or indirectly. We investigated outpatient skin disease diagnoses at the dermatology clinic to determine the effect of the COVID-19 pandemic on these patients. : We conducted a retrospective study using the International Codes of Diseases data from the outpatient department of Dermatology clinic, Vajira hospital, Navamindradhiraj University, Bangkok, Thailand from January 2019 to June 2021. : A total of 20,915 patients with 34,116 skin diagnoses were included in the study. The average weekly dermatologic clinic visits remained unchanged between the years with and without COVID-19 pandemic. While the percentage of xerosis cutis, other skin infections (syphilis and parasitic infections), hair and nail disorders, pigmentary disorders, benign skin tumors and drug eruptions were significantly decreased during the COVID-19 pandemic years, the percentage of other dermatitis, fungal and viral skin infections, acne, psoriasis, urticaria, vesiculobullous and autoimmune diseases were increased. : The COVID-19 pandemic had a minimal effect on the average weekly skin clinic visits, but the diagnosed skin diseases pattern was affected. Knowing the pattern of skin diseases may help aid hospitals to better prepare for future pandemics in securing appropriate medications and supplies and training the medical teams.