Meglumine antimoniate (MA) is one of the most common treatments for leishmaniasis in the world, which has various side effects and may have effects on the reproductive system of patients who use this drug. In this study, an attempt was made to investigate the effect of long-term administration of MA on histomorphometry and histopathology of testicular tissue in mice. Forty NMRI mice were divided into four study groups: in the control group (eight mice) for 30 days daily, a 0.5 cc physiological serum was administered intraperitoneally. In the second, third, and fourth groups (eight mice in each), MA at a dose of 20, 60, 120 mg \({\text{Sb}}^{\text{v}}\) /kg for 30 days was administered intraperitoneally, respectively. On the 30 th day after the start of the study, mice of all groups were sacrificed, and after opening the right scrotum, their testes were removed from the body for histopathological sampling and were fixed in Bouin’s solution to prepare pathology sections to observe the results. In pathological examinations of testicular tissue in the present study, following the use of MA, it was seen that degenerative lesions such as reduced cell number and the presence of empty spaces inside the epithelial tissue of seminiferous tubules intensified with increasing dose. In the present study, the use of MA significantly reduced indicators related to testicular tissue function including meiotic index, Johnson ranking, spermatogenesis percentage, and seminiferous tubule epithelium height in all treatment groups. According to the results of the present study, the administration of MA has negative effects on testicular function and fertility of male mice in a dose-dependent manner.
