Our study concerns eight pregnancies, six of which were successful, in four patients with paroxysmal nocturnal hemoglobinuria (PNH). Several complications of PNH during pregnancy were prevented: chronic anemia, folate and iron deficiency, and deep-vein thrombosis. During puerperium, acute hemolytic crises, most probably triggered by delivery, were observed in two patients. Thrombotic complications could be prevented by early initiation of an anticoagulant therapy after delivery. The only neonatal complication, observed in two cases, was isoimmune hemolytic anemia related to the multiple blood transfusions received before and during pregnancy. These results show that successful pregnancies are possible in women with PNH provided that both the obstetricians and physicians in charge monitor the pregnancies closely.