Inherited thrombophilia has been associated with obstetric complications through mechanisms that are not yet fully elucidated. The aim of this study was to investigate the relationship between specific obstetric adverse outcomes and factor V Leiden and prothrombin G20210A mutations.Forty-five women with adverse pregnancy outcome defined as severe pre-eclampsia, abruptio placentae, intrauterine growth restriction and stillbirth, were tested for factor V Leiden and prothrombin G20210A mutations. The control group comprised 100 women with at least one normal pregnancy and no history of thrombosis.Overall, 13 women with one or more of the above-mentioned pregnancy complications (28%) had either thrombophilic mutation, as compared with six in the control group (6%) (p < 0.001, odds ratio (OR) 6.1; 95% confidence interval (CI) 1.9-20). The factor V Leiden mutation was detected in ten of the women with complicated pregnancies (22%) and in four of the controls (4%) (p < 0.001, OR 6.6; 95% CI 1.7-27.2). The prothrombin G20210A mutation was detected in three women in the group with complications (6%) and in two of the controls (2%) (p = 0.17, OR 3.4; 95% CI 0.4-30.5). Compared to controls, the prevalence of the factor V Leiden mutation was significantly higher in the subgroups of severe pre-eclampsia, abruptio placentae and fetal growth restriction. The prevalence of the prothrombin G20210A mutation does not appear to be significantly different from that in the controls in any of the groups studied.Our data suggest that inherited thrombophilia, and specifically the factor V Leiden mutation, may be associated with adverse pregnancy outcome. The role of the prothrombin G20210A mutation remains to be elucidated.