The protozoan T. gondii infects human and animals. The parasite can alter the generative system affecting fertility. This work studied the impact of toxoplasmosis on male generative system in rats. 49 laboratory breed Wistar rats were divided into group I containing 35 rats and group II 14 control. About 0.5ml of the withdrawn peritoneal exudates contained 2 x 106 tachyzoites RH strain type I was inoculated intraperitoneally into each rat of GI. On days 10, 20, 30, 40, 50, 60 & 70 post-inoculation (PI). Seven rats were anesthetized 5 from GI and 2 from GII each time. Both testes were removed, weighed, body and testis weight ratio (BTR) was calculated. Left testis was kept for histopathology and right testis was processed for tissue homogenate preparation and estimation of intratesticular testosterone (ITT) and lactate dehydrogenase (ITLDH). For BTR, slightly or no difference was detected. Mean level of ITT was significantly decreased in GI throughout the 70 days, ITLDH was higher in GI especially on days 40, 50, 60 & 70 (P < 0.05). Detection of tachyzoites within seminiferous tubules on day 10 PI, with aggregation on day 30. Engorged blood vessels, degenerated, oedematous vessels, empty seminal vesicle with increasing number of tachyzoite and bradyzoite in cyst were detected. In
GII, germinal cells were available with non detectable pathology. Toxoplasmosis altered hormonal ITT and ITLDH which was linked to testicular damage in male rats.