The incidence of kidney stones has increased worldwide in association with economic development; however, treatment modalities are not satisfactory. This study aimed to explore the effect of cod liver oil on the prevention of kidney stone formation in male rats. Renal stones were induced by oral administration of 0.75 % ethylene glycol (EG) with 1% ammonium chloride for 10 days. Twenty-four male rats were separated into 4 groups. Group 1 served as control; group 2 received EG plus NH4CL; group 3 was pre-treated with CLO (480 mg/kg body weight) for 2 weeks, followed by EG plus NH4Cl administration; group 4: was post-treated with CLO plus EG plus NH4Cl. At the end of the experiment, histopathological analysis and the degree of calcification in the renal tissue were analyzed. Blood levels of triglycerides, cholesterol, urea, creatinine, calcium, and phosphorus were determined. Lipid markers, antioxidant markers, and oxidative stress indicators were assessed in renal tissues. EG caused increases in kidney weight, malondialdehyde levels, and the reduction of glutathione, catalase, and SOD in kidney tissues. The results showed a protective effect of CLO against EG-induced nephrolithiasis concomitant with a reduction effect on lipid parameters, amelioration of kidney function markers, and a restoration of antioxidant status. No stone formation was detected in both kidneys, and the amount of calcification was significantly reduced in CLO groups in comparison to the EG group. In conclusion, CLO could be useful in preventing stone formation in rats through modulating lipid profiles and renal membrane lipids and enhancing antioxidant status.