Background: Idiopathic nephrotic syndrome (INS) is a clinical syndrome characterized by massive loss of urinary protein leading to hypoproteinemia and edema. It is reported that the immune system plays an important role in pathogenesis and pathophysiology of INS. The moncyte chemotactic protein-1 plays an important role in the recruitment of monocytes/macrophages into renal tubulointerstitium. Aim of the study: The aim of our study was planned to measure the urinary level of monocyte chemotactic protein 1(MCP-1) in children with INS during remission and relapse, and predict steroid responsiveness. Methods: This prospective study included 50 patients with nephrotic syndrome (NS) following up in Pediatric Nephrology Clinic, Benha University subdivided into 2 groups: group A (cases in remission) & group B (cases in activity). Also, 20 age and sex matched healthy children have been included as a control group. Results: We found a significant increase in urinary MCP-1 in INS patients as compared to control group (p < 0.001). Also, our study showed that group B had the highest levels of uMCP-1 followed by group A then control group (p