A case of Androgen Insensitivity Syndrome in one of three sisters who presented with primary amenorrhea, female phenotype with fully developed female breasts, absent uterus and ovaries, a short blind-ending vagina, absent axillary hair, scanty pubic hair, and a male karyotype is presented here. Approach to correct diagnosis and differentiation of Androgen Insensitivity Syndrome from other causes of primary amenorrhea are discussed. Appropriate management including surgical, medical and psychological aspect and the option of eventually marrying and establishing a family of their own are also presented. Ethical issues regarding disclosure of the diagnosis to patients with Androgen Insensitivity Syndrome are also tackled. (Author)