Background: nephrotic syndrome is a prevalent glomerular condition that characterized by edema, hypoalbuminemia, hyperlipidemia, and severe proteinuria. is also lost in the urine of children with nephrotic syndrome, and the in urine causes a shortage in several important plasma proteins, such as Protein S, anti-thrombin III and protein C. This study aimed to evaluate the effect of nephrotic syndrome on coagulation status. Methods: This Case-control study was conducted at Pediatric Nephrology Unit at Zagazig University Hospitals over a period of six months. The study included 40 nephrotic children in different disease activity, and 40 healthy controls matched for age and sex. All participants underwent to complete history-taking, physical examination and laboratory studies including coagulation profile and platelet indices. Results: Plasm level of protein S, Protein C and AT III during activity (onset and relapse) were significantly lower than their level at remission and in healthy controls. The mean level of fibrinogen was significantly higher during activity than its level during remission period and in control group. Correlations between changes in coagulation parameters and biochemical findings were also investigated. Serum albumin levels were positively correlated with plasma AT III, PC, and PS (P<0.001). Mean platelet number was significantly higher during activity (onset and relapse) than in remission period and in control group. Conclusion: This study reveals that the haemostatic abnormalities in nephrotic children involve mostly high fibrinogen and platelet count. But, low protein S, protein C, Antithrombin III, and mean platelet volume. Variations of values may be related to disease state.