The hereditary fever syndromes are a group of monogenic diseases that are characterized by recurrent episodes of fever and inflammation. The differential diagnosis is broad and includes, among others, infections, non-infectious inflammation and malignancy. The hereditary fever syndromes include familial Mediterranean fever (FMF), hyper-IgD syndrome (HIDS) and tumor necrosis factor receptor-1-associated periodic syndrome (TRAPS). The characteristics of the individual syndromes (length of the febrile episode, localization of accompanying pain, lymphadenopathy, age of onset, mode of inheritance) allow an initial disease assignment. The diagnosis is confirmed with molecular genetic analysis of the genes MEFV / Pyrin / Marenostrin (FMF, autosomal recessive), MVK / mevalonate (HIDS, autosomal recessive) or TNFRSF1A/p55 (TRAPS, autosomal dominant). The identification of the molecular basis of the disease allows these syndromes to be distinguished from acquired disorders with an activation of the innate immune system (“hereditary autoinflammatory syndromes”), and increasingly, to their specific treatment.