Androgenetic alopecia (AGA) is the most common type of hair loss in adults, but it also occurs in adolescents, though its prevalence among this younger population is not well established. The purpose of this study was to evaluate the clinical manifestations and endocrine status of adolescent patients with AGA in Korea. This 5-year (January 2001-August 2005) clinical study involved 43 adolescent patients with AGA. Testosterone and dehydroepiandrosterone sulfate (DHEA-S) laboratory studies were undertaken to investigate androgenic hormonal effects. Hair loss severity was categorized using the Hamilton-Norwood and Ludwig classifications. Gender ratio showed a male predominance (M : F, 35:8), and a mean age at onset of 16.8 years. These adolescent patients showed milder symptoms than adults, and a family history of alopecia was found in 72.1%, which is greater than that reported in adults, which ranges 30.9-64.5%. Seborrheic dermatitis (27.9%) was the condition most commonly associated with AGA among our study subjects, followed in descending order by acne vulgaris and atopic dermatitis. Serum levels of testosterone and DHEA-S were within normal limits, except in one subject. Our study shows the clinical characteristics of AGA in Korean adolescents.