ABSTRACT Aim: To assess the clinical significance of inherited thrombophilia [IT] for the development of some pregnancy complications. Material and methods: The incidence of the following factors was studied in 97 pregnant women with pregnancy complications and in 103 controls: R506Q mutation encoding Factor V Leiden [FVL] synthesis, Prothrombin G20210A mutation, T677 methylenetetrahydropholate reductase mutation [MTHFR], 4G/4G polymorphism of the plasmogen activator inhibitor [PA/4G/4g]. Among 97 patients in the group studied 39 had early onset severe preeclampsia [PE], 14- placental abruption [AP] without PE, 18- intrauterine growth restriction [IUGR] without PE, 12- stillbirth [SB] without PE, 14- habitual spontaneous abortions [HAS]. The control group included 103 clinically healthy pregnant women with at least one previous uneventful pregnancy, without history of thromboembolic disorders. In addition, patients with severe PE with and without IT were compared regarding g. a. and birthweight at delivery and intrauterine fetal loss rate. DNA analysis was performed according to internationally accepted standards. P regnancy outcomes were ascertained from hospital records. Statistical significance (p<0.05) was assessed by means of Student's t-test. Results: FVL mutation was found in 23,7% (23/97) of the patients from the studied group and in 5,8% (6/103) of the controls. Prothrombin G20210A carriers were 11% (11/97) of the studied and 3,8% (4/103) of the controls, while with PAI 4G/4G polymorphism they were 30,9% (30/97) and 14,5% (15/103) respectively. MTHFR T677 was not more frequent in the studied group (8,2%) compared to the control one (29%). Eight of the patients (9,6%) were carriers of more than one mutation, in 22 cases with early onset severe PE and IT gestational age and birthweight at delivery were lower than in the cases with severe PE without IT while intrauterine fetal loss rate did not differ significantly between two groups. Conclusions: Inherited thrombophilia is found more frequently in women with pregnancy complications like PE, IUGR, AP, SB, HSA. The incidence of homozygous MTHFR T677 is not higher in these cases. IT worsens the prognosis of severe PE. The diagnosis of IT is important since anithrombotic therapy has to be considered to protect the mother and the fetus.