Abstract: A 38-year-old female presented with irregular menstruation and hirsutism that started at age of 16 and diagnosed with polycystic ovary syndrome at age of 29 with elevated testosterone. When treated with ethinestradiol cyproterone tablets, her menstruation returned to normal and androgen levels was not changed. At age of 38 she was referred to the hospital with infertility, a diagnosis of nonclassical 21-hydroxylase deficiency was confirmed using 17-hydroxyprogesterone, dehydroepiandrosterone-sulfate, a cosyntropin-stimulation test and genetic test. This case suggested that nonclassical congenital adrenal hyperplasia should be considered when a patient is presented with oligomenorrhea, hirsutism with hyperandrogenemia and infertility.