Background: Type 1 diabetes mellitus could be associated with other autoimmune diseases, such as autoimmune thyroid disease, celiac disease, but the association with Familial Mediterranean Fever is rare, we describe a case of a boy with type 1 Diabetes Mellitus associated with Familial Mediterranean Fever (FMF)Case presentation: A 13 year old boy already suffering from Diabetes Mellitus type 1 since the age of 4 years, came to our attention because of periodic fever associated with abdominal pain, chest pain and arthralgia. The fever appeared every 15-30 days with peaks that reached 40°C and lasted 24-48 hours. Laboratory investigation, were normal between febrile episodes, but during the attacks revealed an increase in inflammatory markers. Suspecting Familial Mediterranean Fever molecular analysis of MEFV gene, was performed. The genetic analysis showed homozygous E148Q mutation. So Familial Mediterranean Fever was diagnosed and colchicine treatment was started with good response.Conclusion. Familial Mediterranean Fever could be associated with other autoimmune diseases such as Ankylosing Spondylitis, Rheumatoid Arthritis, Polyarteritis Nodosa, Behcet disease, Systemic Lupus, Henoch-Schönlein Purpura, and Hashimoto’s Thyroiditis. Association of type 1 Diabetes Mellitus and Familial Mediterranean Fever has been newly reported in the medical literature, this is the third association of these two diseases described in the medical literature so far.