The present study was designed to study effect of watermelon extract on fertility of experimental rats. The biological evaluation on male rats Sprague Dawley Strain (250 -270 g) the study continued for 28 days. Five groups of rats, each contains 5 rats, were fed on different tested diets Group1: control group rats fed on basal diet. Group 2: fed on basal dietand treated daily orally with 100mg/kg body weight of watermelon pulp methanol extract. Group 3: fed on basal diet and treated daily orally with 200mg/kg body weight of watermelon pulp methanol extract. Group 4: fed on basal diet and treated daily orally with 100mg/kg body weight of watermelon seeds methanol extract. Group 5:fed on basal diet and treated daily orally with 200mg/kg body weight of watermelon seeds methanol extract. Chemical, biological, biochemical and histological tests were carried out. The results of this study showed that watermelon contains high amount of moisture and carbohydrates in watermelon seeds extract and watermelon pulp extract and low amount of fat.