Petroleum ether, chloroform and ethanol extracts of the seeds of Melia azedarach Linn. administered orally to male rats at the dose level of 25 mg/100 g body weight for 48 days showed antispermatogenic activity, as the number of spermatocytes, spermatids and spermatozoa was decreased. The total cholesterol content was increased while protein and glycogen contents were decreased. The acid phosphatase content was also decreased while that of alkaline phosphatase increased. At the same time the weight of caput and cauda epididymis, prostate gland, seminal vesicle and Levator Ani muscle was decreased indicating its antiandrogenic property. Of the three extracts, the petroleum ether extract was more potent in its antispermatogenic and antiandrogenic activities and did not produce any sings of toxicity upto a dose of 25 mg/100 g body weight oral administration. After subjecting it to preliminary phytochemical screening the petroleum ether extract showed positive tests for steroids and saponins.