One hundred and thirty-seven patients attending the gynaecological endocrine clinic at Maharaj Nakhon Chiang Mai hospital between April 1, 1982 and July 31, 1987 were studied. Detailed history, physical and pelvic examination were obtained on all patients, followed by progesterone withdrawal test and other appropriate laboratory studies including thyroid and reproductive hormone profiles. The most common cause of secondary amenorrhea in this study was hypothalamic-pituitary dysfunction (54.7%), not unlike those reports from other foreign series. However, it was notable that nearly 40 per cent of our patients in this group experienced amenorrhea after discontinuation of contraceptive steroids. Premature ovarian failure was the second leading cause of amenorrhea in our patients (13.9%) and, perhaps, deserve future detailed studies. The other causes of amenorrhea in decreasing frequency were: hyperprolactinemia (11.7%), hypothalamic-pituitary failure (8.0%), Asherman's syndrome (5.1%) and androgen excess (2.9%). Primary hypothyroidism was a rare cause of amenorrhea in this study.