Familial Mediterranean fire (FMF) is an autosomal recessive disorder with episodes of peritonitis, pleuritis and arthritis usually associated with fever and affecting ethnic groups (Turkish, Arab, Armenian, Jewish) often around the Mediterranean. The genetic mutation frequency in FMF etiology is reported to be 1/8-16. Mutations in the MEFV (MEditerranean FeVer) gene encoding the protein known as pyrin or meranostrin appear to be the cause of the disease in most cases. Obsessive compulsive disorder (OCD) is a chronic psychiatric disorder characterized by obsessions and compulsions, which cause significant impairment of social, occupational functioning and social activities of individuals. Genetic studies show that both genetic and environmental and cultural factors play roles in etiology and the emergence of symptoms. In some studies suggesting genetic linkage between OCD and genes in the serotonergic-dopaminergic pathway, linkages were found in 3q, 6q, 7p, 1q and 15q non-parametric chromosome regions, the strongest linkage being obtained on chromosome 3q27-28. It is aimed to contribute to the literature by considering possible common etiopathogenesis and treatment approaches of FMF and OCD coexisting in which genetic factors are known to be present in these cases.