Hyperandrogenism or androgen excess is a common endocrine disorder of women of reproductive-age, with a prevalence of 5-10%. The majority of patients with hyperandrogenism will have polycystic ovary syndrome. Hyperandrogenism presents a complex diagnostic challenge for both the practicing physician and the clinical investigator. Clinical manifestations of hyperandrogenism include hirsutism, acne, androgenic alopecia, and virilization. Hirsutism, defined as excessive growth of terminal hair in women in a male-like pattern, is the most commonly used clinical diagnostic criterion of hyperandrogenism. The presence of hirsutism is usually determined by using a standardized scoring system of hair growth. Depending on the definition, hirsutism is present in up to 80% of patients with hyperandrogenism. Acne and androgenic alopecia are other common androgenic skin changes, and might be observed without hirsutism in some hyperandrogenic women. However, isolated presence of any of these manifestations is not used as a diagnostic criterion for hyperandrogenism. Virilization is a relatively uncommon feature of hyperandrogenism, and its presence often suggests an androgen-producing tumor. A thorough history and a focused clinical examination are extremely helpful in diagnostic evaluation of patients with suspected hyperandrogenism.