The term periodic fever and diseases classified under periodic fever, have particular situation in pediatrics. Periodicity and fever are the hallmark of these syndromes, though there could be other symptoms and signs in each syndrome. On the other hand, most of these syndromes have familial pattern. Since some of these syndromes are common in north-west Iran, the understanding and recognition of these diseases seems to be necessary. Nowadays at least seven periodic fever syndromes have been explained in pediatrics: The first one is FMF and the last and new one is PFAPA. The rest of them are: Hyper IgD, FCAS, Muckel- Wells, CINCA, and TRAPS.