&NA;Serum FSH and LH levels were determined at different time intervals after the subcutaneous administration of 100 &mgr;g LHRH to 24 females. Serum FSH levels were of the same order in the oligomenorrhea‐amenorrhea and the Stein‐Leventhal group of patients but elevated in gonadal failure. There was a great degree of overlap between serum LH values in the three groups. Gonadal failure patients, however, could be distinguished from the other two groups because these patients had an elevation of both serum FSH and LH, and the response to LHRH was considerably exaggerated in comparison to the other two groups.