Background: Urinary calculi are a common and severe problem, which are formed by urolithiasis or by the formation of calcium oxalate (CaOx) crystals in the kidneys. Many treatment options such as drugs, various herbal preparations, surgical removal of the stones, and extracorporeal shock wave lithotripsy have been applied for this condition. The aim of this study is to assess the effects of the drug amlodipine in an experimentally induced urolithiasis rat model. Materials and methods: The effect of 5 mg/kg amlodipine was studied in rats that were first treated with 1% ethylene glycol and 1% ammonium chloride for 21 days to induce urolithiasis. The weight differences and the levels of calcium, magnesium, and phosphate were measured in serum and urine. In addition, urine CaOx level was defined and histopathological analyses were performed on the kidneys. Results: Urolithiasis caused a significant increase in both serum and urine parameters compared with healthy rats. Urolithiasis plus amlodipine administration increased the levels of these same parameters. Urine CaOx level was high in urolithiasis rats and was also increased by urolithiasis plus amlodipine administration. The weight of the rats decreased in the urolithiasis plus amlodipine group when compared with the urolithiasis group. Histopathological examinations revealed extensive intratubular crystal depositions and degenerative tubular structures in the urolithiasis group and the amlodipine treatment group. Conclusion: We showed that amlodipine may increase susceptibility to urolithiasis by raising hyperoxaluria and hypercalciuria. Further studies should be performed to elucidate the urolithiasis activity of amlodipine and to confirm the data.