BACKGROUND Acne vulgaris is a distressing condition that affects the majority of adolescents, but the impact of acne vulgaris on the psychological aspects in this age group is poorly understood. OBJECTIVE The purpose of this study was to determine the prevalence of acne, and the level of emotional, social, and functional impairments among Korean adolescents with acne. METHODS Five hundred four middle school students (13~16 years) participated. The severity of acne was graded by visual examination using the Korean Acne Grading System. Self-reported questionnaires, including subjective acne severity rating, the Self Image Questionnaire, the Rosenberg Self-Esteem Questionnaire, the Index of Peer Relations, and the Beck Depression Inventory were used to assess psychologic status. RESULTS There was a prevalence of acne in 78.9% of the study samples, with 10.2% of students having moderate-to-severe acne. Acne was more prevalent and severe in boys than girls. Participants with severe acne and girls had higher levels of emotional and social impairments. The longer the acne persisted, the more stress the students felt. The degree of stress and extent of self-image impairment were related to subjective severity more than objective grading. CONCLUSIONS Acne is a common disorder among Korean adolescents and appears to have a considerable impact on mental health. Dermatologists should be aware of the importance of basic psychosomatic treatment in conjunction with early medical, educational intervention in the management of acne.