This study was done to find the potential renal protective effects of sildenafil and its underlying mechanisms in mice with adenine-induced CKD. For the experiment, 40 male mice were split into four groups. The control group (A) received the same food without medication until the research ends, while the other three collections (B, C, and D) were given adenine (0.25% w/w in feed daily for 8 weeks), groups (C and D) were given sildenafil (0.5 and 2.5 mg/kg) respectively orally every day for 30 days, and then blood samples were taken to assess the function of the kidneys (Urea, total protein, and creatinine), total antioxidant capacity (TAC), superoxide dismutase (SOD), and catalase (CAT) in addition to kidney histopathology, as well as body and kidney weight. Administration of adenine caused weight loss, increased TAC, SOD, and CAT, and increased plasma concentrations of urea, total protein, and creatinine. Damage-related renal histopathological indicators (fibrosis and inflammation) were considerably elevated by adenine. Most of the aforementioned metrics improved with sildenafil, indicating that it might be utilized as an adjuvant treatment for CKD in people through antioxidant, anti-inflammatory, and anti-apoptotic mechanisms.