Familial Mediterranean fever (FMF) is an autosomal recessive disorder characterized by recurrent febrile attacks accompanied by serosal and synovial membrane inflammation. FMF is caused by mutations in the MEFV gene and are found usually among Mediterranean populations, Armenians, Turks, Arabs and Jews. The aim of this study was to determine the frequency of MEFV gene mutations among FMF patients in the Azeri Turk population in North-West of Iran.In this descriptive study, 130 FMF patients with Azeri Turk origin were screened for mutations in four exons (2, 3, 5 and10) of MEFV gene. Genomic DNA was extracted from whole blood and entered in ARMS-PCR and PCR-RFLP reactions. When cases were negative in ARMS-PCR and PCR-RFLP, the exons were amplified and subjected to direct sequencing.Our results showed that the most common mutations in this study population was M694V (40.19%) followed by E148Q (17.64%), V726A (13.72%), M680I (12.74%) and M694I (2.94%) mutations. Four new mutations including K618N, K716M, S614F and G136E were identified in our study.The prevalence of five common mutations in our study was highly similar to previous studies analysing the Mediterranean basin populations. Investigation by sequencing also revealed four new variants in the study population. The main genotypephenotype correlation finding was the presence of M694V mutation in homozygote or compound heterozygote state in the patients with renal manifestations.