This study was carried out to evaluate the effects of Annona muricata ethanolic leaf extract on the testes of adult wistar rats. Twenty wistar rats weighing between 180 – 205g were used for the study. They were designated into four groups (A, B, C & D) of five animals each. Group A animals served as the control and were orally administered 0.3ml of distilled water; the experimental groups B, C & D were orally administered 0.2 ml, 0.4ml and 0.6ml of Annona muricata ethanolic leaf extract respectively for twenty eight days. Twenty four hours after the last administration, the animals were weighed, sacrificed under the influence of chloroform vapour and dissected. Testes tissue were removed, weighed and fixed in 10% formalin for histological studies. The final body weight of groups C and D decreased significantly (P