Introduction: Familial Mediterranean fever (FMF, MIM# 249100) is an autosomal genetic disease. FMF shows a marked ethnic distribution being most frequently observed in Turkish, Armenian, Jewish and Arabic communities. Since the cloning of the MEFV gene, about 280 mutations have been associated with FMF. M694V, V726A, E148Q, M694I, and M680I are the five most frequently encountered mutations. Objective: The aim of this work was to correlate the clinical phenotypes of FMF patients to their gene mutation. Patients and methods: The study was done on 55 patients with FMF who were diagnosed primarily clinically using Turkish pediatric criteria. Genetic identification of their gene mutation was performed and only patients with definite identified mutation in MEFV were included. Results: Fever was the most prevalent manifestation in our patient as 96.3% of them experienced fever and the second most frequent symptom was abdominal pain 90.9% followed by chest pain 81.8%. Family history was positive in 61.8%. At diagnosis fifteen patients had amyloidosis at (27.3%) while forty patients did not have elevated amyloid (72.7%). Fifty one patient showed good response to colchicine (92.7%) while only four did not show response (7.3%). The severity of attacks were mild in 29 patients (52.7%) and moderate in 6 patients (10.9%) and severe in 20 patients (36.4%). M694V was the most prevalent mutation followed by M694I, V726A, M680I, R761H and K695R respectively. Conclusion: In Egypt no significant difference between homozygous and heterozygous FMF patients regarding their clinical presentations but type of mutation affects the severity of clinical presentation.