Serum cystatin C is a non glycated basic protein produced at a steady rate from all nucleated cells. Our work aims to prove the effectiveness of cystatin C, interleukin-6 (IL-6) and interleukin-8 (IL-8) as markers for early glomerular affection either in glomerulonephritis patients or renal transplant recipients. We studied 5 groups of patients: Group I were 30 adult glomerulonephritis patients with different pathology types, Group II were 15 pediatric patients suffering from glomerulonephritis, Group III and Group IV were kidney transplant recipients studied twice one week and one month following the operation and finally Group V were 20 normal control subjects. All our patients were subjected to clinical examination and lab investigations including complete blood count, kidney functions, creatinine clearance, liver functions, serum electrolytes, urine analysis, 24 hours urinary proteins, cystatin C, IL-6 and IL-8. We found that cystatin C in the studied groups was statistical significantly higher in comparison to the control group (p=0.000). But it did not differ statistically between Group I and Group II (p=0.895), this means that cystatin C was not affected by the patients age. Also cystatin C was highly correlated to creatinine and creatinine clearance in all the studied groups. Both serum IL-6 and IL-8 were not statistically significant in comparing either each of our groups to the control group or to each other. We may conclude that cystatin C might be used as a marker for early glomerular affection either in glomerulonephritis or kidney transplant recipients.