Unilateral ureteral obstruction (UUO) is a widely used animal model to study renal pathophysiology and the progression of kidney injury. This study investigates the histopathological and biochemical changes in the kidneys of rats subjected to UUO. The rats were divided into two groups: the experimental group with unilateral ureteral obstruction and the control group. Kidney tissues were examined histologically for structural changes such as tubular dilation, fibrosis, and inflammation. Biochemical analyses measured key markers of renal function, including serum creatinine, blood urea nitrogen (BUN), and antioxidant enzyme activity. The findings revealed significant renal damage in the obstructed kidneys, with histopathological evidence of tissue injury and biochemical markers indicative of renal dysfunction. This study provides valuable insights into the mechanisms of kidney injury in UUO and emphasizes the need for therapeutic strategies to mitigate renal damage in obstructive nephropathy.