Maternal floor infarction (MFI), massive perivillous fibrin deposition (MPVFD), and fetal thrombotic vasculopathy (FTV) are specific placental lesions with associations to recurrent adverse fetal outcomes and with maternal thrombophilia. We studied the frequency of a range of acquired and genetic maternal thrombophilias in MFI (40 cases), MPVFD (87 cases), FTV (7 cases), and FTV+MPVFD (4 cases). Thrombophilias were identified in 16 (40%), 20 (23%), 5 (71%), and 2 (50%) of these lesions, respectively. Seventy-seven percent of the identified thrombophilias were genetic, and 23% were acquired. The most common genetic thrombophilia was protein S deficiency, which constituted 14 of the 36 genetic thrombophilias (39%). We advocate full maternal thrombophilia testing when the diagnosis of MFI, MPVFD, and FTV is made by placental pathology examination. Because of the possible contribution of paternal thrombophilic mutations to the fetal genotype, it would be desirable to test the whole family as well.