Introduction: Idiopathic nephrotic syndrome is a clinical syndrome marked by a significant loss of urine protein, resulting in hypoproteinemia and edema.The recruitment of monocytes/macrophages into the renal tubulointerstitium is aided by the moncyte chemotactic protein-1. Aim of the study: The aim of our study was planned to measure the level of monocyte chemotactic protein 1 in the urine of children with idiopathic nephrotic syndrome during disease activity and remission as well as in steroid sensitive and steroid resistant cases to identify a possible predictive biomarker of disease activity and/or steroid responsiveness. Methods: This prospective study comprised 50 patients with nephrotic syndrome who were followed up on at Pediatric Nephrology Clinic and Department, Benha University, and were divided into two groups: group A (cases in remission) and 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 moncyte chemotactic protein-1(uMCP-1) in idiopathic nephrotic syndrome patients as compared to control group (p < 0.001). Also, the greatest levels of uMCP-1 were found in group B, followed by group A, and then the control group (p