Summary: Laboratory investigation of thrombophilia is aimed at detecting the well-established hereditary and acquired causes of venous thromboembolism, including activated protein C resistance/factor V Leiden mutation, prothrombin G20210A mutation, deficiencies of the physiological anticoagulants antithrombin, protein C and protein S, the presence of antiphospholipid antibodies and increased plasma levels of homocysteine and coagulation factor VIII. In contrast, investigation of dysfibrinogenemia, a very rare thrombophilic risk factor, should only be considered in a patient with evidence of familial or recurrent thrombosis in the absence of all evaluated risk factors mentioned above. At this time, thrombophilia investigation is not recommended for other potential hereditary or acquired risk factors whose association with increased risk for thrombosis has not been proven sufficiently to date. In order to ensure clinical relevance of testing and to avoid any misinterpretation of results, laboratory investigation of thrombophilia should always be performed in accordance with the recommended guidelines on testing regarding the careful selection of patients, time of testing and assays and assay methods used. The aim of this review is to summarize the most important aspects on thrombophilia testing, including whom and when to test, what assays and assay methods to use and all other variables that should be considered when performing laboratory investigation of thrombophilia.Keywords: acquired risk factors, hereditary risk factors, laboratory investigation of thrombophilia, venous thromboembolism Sa`etak: Cilj laboratorijskog ispitivanja trombofilije je otkrivanje ve} ustanovljenih naslednih i ste~enih uzroka venskog tromboembolizma, me|u kojima su aktivirana rezistencija na protein C/mutacija faktora V Leiden, mutacija protrombina G20210A, deficijencija fiziolo{kih antikoagulanasa antitrombina, proteina C i proteina S, prisustvo antifosfolipidnih antitela i povi{enih nivoa homocisteina i faktora koagulacije VIII u plazmi. Nasuprot tome, ispitivanje disfibrinogenemije, veoma retkog faktora rizika za trombofiliju, treba uzeti u razmatranje samo kod pacijenata kod kojih postoje dokazi o porodi~noj ili rekurentnoj trombozi uz odsustvo svih navedenih faktora rizika. U ovom trenutku, ispitivanje trombofilije se ne preporu~uje za ostale potencijalne nasledne ili ste~ene faktore rizika, ~ija povezanost sa pove}anim rizikom za trombozu jo{ nije nedvosmisleno dokazana. Kako bi se obezbedila klini~ka relevantnost testiranja i izbeglo pogre{no tuma~enje rezultata, laboratorijsko ispitivanje trombofilije trebalo bi uvek vr{iti u skladu s preporukama za testiranje koje se odnose na pa`ljiv odabir pacijenata, vreme testiranja i testove i metode koji se koriste. Cilj ovog preglednog ~lanka je da se ukratko predstave najva`niji aspekti testiranja trombofilije, izme|u ostalog, koga i kada testirati, koje testove i metode upotrebiti i koje sve varijable treba uzeti u obzir prilikom laboratorijskog ispitivanja trombofilije.Klju~ne rije~i...