Thrombophilia is defined as the general name for a group of genetic and acquired situations, arising from defects of hemostasis mechanism and generating tendency to thrombosis. Examples of the acquired risk factors that increase the tendency to thrombosis are venous catheters, sepsis, surgery, hyperlipidemia, congestive heart disease, increased lipoprotein a, old age, antiphospholipid syndrome, nephrotic syndrome, hyperviscosity, chronic myeloproliferative neoplasms, paroxysmal nocturnal hemoglobinuria, heparin induced thrombocytopenia, vasculitis, immobility, obesity, major surgery, trauma, burns, malignancy, pregnancy and oral contraceptive usage. Genetic tendency to venous thromboembolism in early ages, even without any known cause, is named as thrombophilia. Factor V Leiden, prothrombin G20210A, methylenetetrahydrofolate reductase gene mutations, factor VIII elevation, protein C, protein S and antithrombin deficiency parameters are suggested for evaluation, in patient groups suspected of inherited thrombophilia. Detection of inherited thrombophilic factors in selected patient groups is a guide in developing treatment strategies and in establishing prognosis. Due to the genetic heterogeneities, each society should determine their thrombophilic risk pool. Thus, with the determination of the risk factors, unnecessary assessments will be prevented and a cost-effective approach can be developed.