Background: The purpose of this study was to examine the effects of exposure to imatinib in the prenatal period on testis development in rats. Methods: Although all the study groups received intraperitoneal imatinib on prenatal days 1-8, no pregnancy occurred in the Imatinib-80 group. Immunohistochemical analysis, TUNEL, c-kit and PDGF staining revealed no difference between the groups in terms of positivity scoring. Results: A significant decrease was detected in total sperm counts in the Imatinib-20 group compared to the control group, but the sperm count was higher in the Imatinib-60 group than in the Imatinib-20 group. At biochemical measurements, the drug increased oxidative stress in the testis and serum in the Imatinib-20 group, but caused a decrease in tissue in the Imatinib-60 group. Thiol measurements revealed a decrease in the testis and serum in the Imatinib-60 group, while an increase in serum measurements was observed in the Imatinib-40 group. Analysis revealed no difference between the groups in terms of protamine and histone gene expression levels in testis tissue exposed to imatinib. Conclusion: Our findings show that prenatal exposure to imatinib can lead to histopathological and biochemical changes in testis tissue, but that no adverse effect occurs in nuclear maturation of germ cells during spermiogenesis.