Recent clinical reports have demonstrated that the progression and prognosis of renal diseases are possibly influenced by apolipoprotein E (apoE) genotypes and alleles. In this study we investigated whether apoE genotypes and alleles can be a prognostic criterion for the steroid responsiveness in childhood nephrotic syndrome. One hundred and seven pediatric patients with primary idiopathic nephrotic syndrome and 83 healthy volunteers were enrolled in the study. Eighty-seven of the patients had steroid-sensitive nephrotic syndrome (SSNS) and 20 had steroid-resistant nephrotic syndrome (SRNS). The varepsilon2 allele frequency and varepsilon2/3 genotype frequency of the SNRS group were statistically higher when compared with SSNS and control groups ( P<0.05). The higher frequency of the varepsilon2 allele in steroid resistant nephrotic patients suggests that the varepsilon2 allele gives a possible genetic predisposition to steroid resistance in our population, but further studies are needed to clarify this subject.