While the role of inherited thrombophilia has been accepted as a cause of recurrent late pregnancy complications, the contribution of mutated thrombophilic genes to implantation failure has not been studied. Proteins involved in fibrinolysis are necessary for trophoblast invasion into the endometrium. This study compared the prevalence of 10 thrombophilic gene mutations among 42 women with a history of recurrent implantation failure after IVF-embryo transfer with 20 fertile control women. Buccal swabs were taken from all of the women for DNA analyses. Women with a history of implantation failure after IVF-embryo transfer displayed a higher prevalence of PAI-1 4G/5G mutations than controls (P = 0.007). No differences in the frequency of the other specific gene mutations were detected. However, the prevalence of total gene mutations among patients with implantation failure was significantly higher than among controls. More than three gene mutations among the 10 genes studied were observed in 74% of women with implantation failure and 20% of controls (P = 0.0004). It is concluded that inherited thrombophilias are associated with implantation failure. This association is manifest by total number of mutations as well as with PAI-1 mutations.