We examined the relationship between placental histology and thrombophilia status in women who were admitted with severe pre-eclampsia/eclampsia, placental abruption, intrauterine growth restriction or unexplained stillbirth. All women had thrombophilia screen at least 10 weeks after delivery (antithrombin III, protein C, protein S, activated protein C resistance, anticardiolipin antibodies, lupus anticoagulant, fasting plasma homocysteine and specific mutations to methylenetetrahydrofolate reductase C677T, G20210A prothrombin gene and factor V Leiden. Placental histology reports were examined to identify the frequency of thrombotic lesions in the placenta including fetal stem vessel thrombosis, fetal thrombotic vasculopathy, placental infarction, perivillous fibrin deposition, intervillous thrombosis and placental floor infarction. During a 17 month period, a cohort of 79 women met the study criteria. Thirty (70%) out of 43 women with abnormal thrombophilia screen had abnormal placental histology. Twenty-eight (78%) out of 36 women with negative thrombophilia screen had abnormal placentae. No specific histological pattern could be identified when thrombophilia positive and thrombophilia negative groups were compared. We propose that there is a poor correlation between thrombophilia status and pathological changes of the placenta in women with severe pregnancy complications.