Familial Mediterranean fever (FMF), hyperimmunoglobulinemia D periodic fever syndrome (HIDS), and tumor necrosis factor receptor-associated periodic syndrome (TRAPS) are hereditary periodic fever syndromes. FMF is caused by mutations in the Mediterranean fever gene, HIDS by mutations in the mevalonat-kinase gene, and TRAPS by mutations in the TNF-receptor superfamily 1A gene. Impaired function of the encoded proteins, i.e. pyrin in FMF, mevalonat-kinase in HIDS, and the p55 TNF-receptor in TRAPS, induces a dysregulated cytokine balance. Clinical manifestations are relapsing fever, serositis, arthralgia, myalgia, and miscellaneous forms of rash. The diagnosis is made through moleculargenetic analysis of mutations of the MEFV-gene (FMF), MVK-gene (HIDS), or TNFRSF1A-gene (TRAPS). Colchicine is the therapy of choice in FMF. HIDS is treated symptomatically. Impaired TNF-alpha regulation in TRAPS can be treated with etanercept.