We studied 60 children affected with idiopathic nephrotic syndrome (INS) plus 20 age and sex matched controls. The children with INS were divided into 3 groups of 20: first presentation, remission and relapse. A complete blood picture and complete urinalysis were done. Serum interleukin (IL)-1beta, IL-6, tumour necrosis factor (TNF) and quantitative urinary beta-2-microglobulin (beta-2-m) excretion were estimated. IL-1beta and IL-6 were significantly higher in the study groups, the first presentation and relapse groups having the highest concentrations. Serum TNF concentration and urinary beta-2-m excretion were significantly higher in the first presentation and relapse groups. Serum IL-1beta, IL-6 and TNF concentrations were able to select positively (100%) the first presentation and relapse groups, while these plus urinary beta-2-m excretion selected negatively (100%) the control group.