Testicular heat shock even for a single short period can induce destruction in testicular tissue and disturbances spermatogenesis. Pioglitazone is an anti-inflammatory and anti-oxidative drug which is used widely in diabetic patients. The main aim of this study is evaluation of effect of pioglitazone on testicular tissue after scrotal heat shock. For this purpose, 54 male Wistar rats were randomly divided in to 9 of 6 rats. In the first three groups which were used as control, the scrotum of animals were submerged in 230c water. In the other three groups (treatment 1), the scrotum was submerged in 430c water for 15 minutes and then the animals received normal saline for 15, 30 and 60 days. In the final three groups (treatment 2) after scrotal heat shock induction, pioglitazone was injected at a dose of 20 mg/kg for 15, 30 and 60 days. At the end of the experimental periods, testicular tissue samples were obtained for pathological and histomorphometerical studies. The results were analyzed with one-way ANOVA and Tukey test and p