Familial Mediterranean fever is an autosomal recessive disorder characterized by recurrent attacks of fever and painful inflammatory manifestations in one or two sites. It is an ethnically restricted genetic disease, found commonly among Mediterranean population, as well as Armenians, Turks, Arabs and Jews. The disease is caused by mutations in the MEFV gene, encoding the Pyrin protein. The objective of this study was to identify the frequency of five common MEFV gene mutations in Iranian children with Familial Mediterranean fever. Thirty unrelated children with clinical manifestation of Familial Mediterranean fever from various parts of Iran were selected and screened for the most common 5 MEFV mutations (M694V, M694I, M680I, V726A and E148Q). The most frequent mutation was M694V (53.3%), followed by M694I (23.3%) and E148Q (13.3%) mutations. We could not detect any mutations in 10% of our patients.