Background: Androgenic alopecia (AGA) is characterized by the local and gradual transformation of terminal scalp hair into vellus hair, which has a shorter and thinner shaft. It is the most common form of hair loss in people with a genetic predisposition for baldness. Objective: The aim of this study was to evaluate the prevalence, AGA type, family history, co-morbidity diseases, stress factors and endocrine factors of AGA patients. Methods: We examined a total of 432 male and female AGA patients who visited for two years at the Department of Dermatology, School of Medicine, Chung-Ang University. Results: There were 2.06 times more men (291 patients) than women (141 patients) among the study subjects. Most of the men were in their twenties (108, 37.1%), however, most of the women were in their forties (42, 29.7%). In the 291 male patients, Norwood class IIIv was dominant (120 patients, 41.2%). In the 141 female patients, Ludwig class I was dominant (87 patients, 61.7%). 219 (75.2%) of the 291 male patients and 81 (73.6%) of the 141 female patients had a family history of AGA. 224 (76.9%) of the 291 male patients and 101 (53.4%) of the 141 female patients had a co-morbidity disorder. The most common among these disorders in both the male and female patients was seborrheic dermatitis. Stress factors were observed in 162 (55.6%) of the 291 male patients and in 78 (55.3%) of the 141 female patients. The most common stress factor in both the male and female patients was work tasks. The serum testosterone levels was increased in 51 (17.5%) of the 291 male patients and in 20 (14.1%) of the 141 female patients. Conclusion: Most of the study results are compatible with those of our previous study. Yet the following results were different: (1) the number of female AGA patients in their forties is increasing; and (2) stress was found to be associated with AGA in both the male and female patients. (Korean J Dermatol 2009;47(7):765~771)