It is known that type 1 diabetes mellitus (type 1 DM) may be associated with other autoimmune diseases. Recently, a patient with an association of type 1 DM and familial Mediterranean fever (FMF) was reported in the medical literature. A 10.5-year-old boy was brought to our clinic with complaints of polydipsia, polyuria and weight loss and was diagnosed as diabetic ketoacidosis due to autoimmune type 1 DM. Insulin therapy was started. Elevated thyroid antibodies associated with diffuse goiter and hypothyroidism led to the diagnosis of autoimmune thyroid disease (ATD), and elevated antiendomysial antibodies and abnormal intestinal biopsy findings led to the diagnosis of celiac disease (CD). L-thyroxine therapy and gluten-free diet were initiated accordingly. At the third-year of follow-up, acute attacks of fever, abdominal pain and chest pain developed. Laboratory investigations, which were normal between the attacks, revealed elevated erythrocyte sedimentation rate, fibrinogen, white blood cell count and pleural effusion on chest X-ray during the attacks. Molecular analysis for FMF revealed compound heterozygous M694I and V726A. The patient responded well to colchicine therapy started at a dose of 1.5 mg/day. We present the second patient with type 1 DM associated with FMF who also had ATD and CD.