Familial Mediterranean fever (FMF) is a genetic disorder characterized by recurrent attacks of fever and inflammation of serosal surfaces. Unlike many mendelian disorders, the mode of transmission has been subject to some controversy as segregation analysis studies have always demonstrated fewer "observed" than "expected" affected individuals. Despite efforts to map the gene causing FMF, no definite linkage has been yet identified. This review analyses the epidemiologic and genetic characteristics in order to evaluate critically the inheritance of the disease and provide a perspective on the current biochemical and molecular genetic studies whose aim is to locate the gene for this disease.