Background: Nephrotic syndrome (NS) is characterised by a loss of albumin, proteins, and other plasma components with comparable bulk. Symptoms include decreasing serum albumin levels, increased blood lipid levels, lipids in urine, and edema. Objective: To estimate serum levels of IgG, IgM, in nephrotic syndrome cases in addition to detect the relationship between IgG/IgM ratio and response to treatment with steroids.   Patients and Methods: The present study was carried out in Benha University Hospital, it comprised 60 children admitted to Nephrology Unit of Pediatric Department of Benha University Hospitals. The cases were divided into four groups: Group A included 15 cases of frequent relapse N.S. (FRNS), Group B comprised 15 cases of steroid-resistant nephrotic syndrome (SRNS), and Group C consisted of 15 cases with infrequent relapses. Additionally, a control group of 15 cases. Results: In our study, serum IgM showed a significant difference between the studied groups (P < 0.001). Pairwise analysis revealed that it was significantly lower in the control group (median = 0.71 mg/ml) than in groups A (median = 1.48 mg/ml), B (median = 1.27 mg/ml), and C (median = 1.62 mg/ml). ROC analyses were conducted to assess the discriminatory potential of serum IgG and IgM levels among the different study groups (Group A, Group B, and Group C) compared to controls. For serum IgG, the analysis for all groups demonstrated significant AUC values, ranging from 0.938 to 0.958, with confidence intervals indicating excellent discrimination. Conclusion: Our findings highlight the potential of serum IgG and IgM levels as diagnostic markers for differentiating nephrotic syndrome cases and provide valuable insights into the pathophysiology and treatment response in these patients.