Familial Mediterranean fever (FMF) is an autosomal recessively inherited disease characterized by recurrent self-limited attacks of fever accompanied by aseptic inflammation of serosal spaces, joints and skin, peritonitis, pleuritis, and arthritis. Clinical features differ according to genetics variants. The aim of this study was to identify relationship between IL-6 -174G/C gene polymorphisms and clinical features, disease severity score (DSS) and proteinuria in children diagnosed with FMF. In this study, 99 children who were followed-up in Gaziosmanpasa University Medical Faculty Department of Pediatrics and diagnosed with Familial Mediterranean fever according to Tel-Hashomer criteria were included. One hundred and fifty seven children who admitted to the hospital with any complain and found healthy included in control group. Genotyping was done for polymorphism in a promoter region of IL-6 gene (G/C at -174). The IL-6 -174G/C gene polymorphism and the clinical features of FMF, proteinuria, the DSS, and the healthy control group were investigated. Data for the clinical features were obtained retrospectively from the electronic records of patients. All of the genotyping of blood samples were done in Medical Genetic laboratory of Gaziosmanpasa University School of Medicine. The results revealed that the distribution of the genotypes and allele frequencies of the IL-6 -174G/C polymorphism were not significantly different between the FMF patients and the healthy controls. The IL-6 -174G/C polymorphisms did not affect proteinuria, the DSS, and the clinical features of FMF patients.