Abstract: The present investigation was under taken to determine the effect of cumulated Camcolit doses (lithium carbonate) in healthy Swiss albino mice concerning the function of testis, epididymis and vas deferens as well as hormonal function. In this study 40 adult male mice taken (23.25 mg mouse-1 - a cumulated dose for a period of 35 days), this dose is equivalent to the low human therapeutic dose and was injected intraperitoneally. Camcolit has no significant effect on mortality but there is significant decrease in both testes and body weight. Its administration induced histopathological changes included: disappearance of spermatogonia and decreased number of spermatocytes which lead to hypo spermatogenesis, hypertrophied nuclei and vacuolated cytoplasm were recorded in Sertoli cells, Intracellular and intercellular vacuoles were formed between germinal cells and Leydig cells have atrophied nuclei with vacuolated cytoplasm. Widening of the ductus epididymis and their cells became cubical with pyknotic nuclei and destruction or total loss of stereo cilia. Sperms disappeared from the vas deferens which suffered from disruption of muscular layers. Also low sperms number with formation of deformed ones with no head, coiled or bent tail. By using radioimmunoassay, it was found that Camcolit reduced serum testosterone level in lithium carbonate exposed male mice.