Background The mechanisms of pathogenesis of steroid-resistant nephrotic syndrome (SRNS) and steroid-sensitive nephrotic syndrome (SSNS) are not well understood. An-tioxidants, such as glutathione peroxidase enzyme (GPx) and its cofactor, selenium, are thought to slow the progress of nephrotic syndrome (NS). Objective To compare selenium levels in SRNS and SSNS pediatric patients. Methods This cross-sectional study was conducted in 51 SRNS and 30 SSNS patients, aged 2 to 18 years, who vis-ited the Pediatric Nephrology Outpatient Clinic at Cipto Mangunkusumo Hospital, Jakarta. Subjects were included by consecutive sampling. Selenium level was measured on venous blood using GC tools MS ™ (Agilent Technologies, inc.). Results Median selenium levels in SRNS patients were 92 (range 42-154) μg/L and in SSNS patients were 93 (range 69-193) μg/L. Conclusion Selenium levels in SRNS and SSNS patients were not significantly different.