Objective: Stanozolol is an anabolic androgenic steroid (AAS) that is widely used by teenagers and athletes in bodybuilding, sports, and athletics. The potential effects of stanozolol in kidney functions have not been defined. In this study we investigated the expression of tumor suppressor protein phosphatase and tensin homolog (Pten) and mRNA levels of phosphatidylinositol 4,5-bisphosphate 3 kinase (Pi3k) and the protein kinase B (Akt1) signaling pathway in rat kidneys treated by stanozolol. Material and Method: Rats were randomized to 5 groups as control, solvent control, steroid (stanozolol), solvent-exercise, and steroid-exercise. Subcutaneous injection of stanozolol (5 mg/kg) was applied for 28 days and swimming exercise was performed 20 min/day, 5 days/week in exercise groups. Expression of PTEN was evaluated by immunohistochemistry. Also, Pten, Pi3k, and Akt1 mRNA expressions were analyzed via RT-PCR. Results: Mesangial cells and renal tubules in the control, solvent control, and solvent exercise groups showed strong (+++) PTEN reactivity against weak PTEN reactivity in the steroid group. Moderate PTEN reactivity was detected in cells of the steroid exercise group. Pten mRNA expression was significantly decreased, and Pi3k and Akt1 mRNA expression were significantly increased in the steroid group versus other groups (p<0.001). Pten expression showed increase while Pi3k and Akt1 expression showed decrease with exercise treatment (p<0.05). Conclusion: Our findings suggest that AAS usage may inhibit PTEN expression in kidneys, which can be associated with increased Pi3k and Akt1 mRNA levels. Exercise performed with AAS usage can be protective on stanozolol-exposed kidneys due to increased levels of PTEN expression and decreased levels of Pi3k and Akt1.