Methomyl was severing toxic if ingested orally & mild- moderate toxic if the inhaled. It is effect on the Acetylcholinesterase (AChE) enzyme by inhibition of this enzyme in humans & animals at high enough doses; in the later, lead to over stimulate of the nervous system. This our research aimed to study toxicopathological changes associated with methomyl toxicity in testes & epididymis of a rats. A total of twenty-four of a rats were, they were divided evenly into three groups after adaption of animals (n=8 rats) as the followings; C control negative group, G1 administered methomyl 0.1 ml/100 gm b.w (1/10 LD50) for 30 days and G2 administered methomyl 0.1 ml/100 gm b.w (1/20 LD50) for 30 days. All animals group sacrificed post 30 days and 1 cmm3 autopsies from testes and epididymis which kept in buffered neutral formalin(10%)for histological observation.Results revealed hypospermatogenesis with abscence of sperm in lumens of the seminiferous tubules, also mild - moderate inflammatory cells infiltration. The epididymus sections revealed reduced in the length of the epithelial lining; in addition to absent of microvillus and abnormal shaped of the sperm inside the lumen. Conclusion: From our data, there were toxicopathological lesions of methomyl of the testes and epididymus of rats when administered different LD50 doses (110 LD50, 120LD50), respectively.