The appropriate time to restart anticoagulation in the postpartum period is not known. The purpose of the present study was to determine whether the timing of postpartum enoxaparin influences hemorrhagic outcomes. A total of 95 women were treated with peripartum enoxaparin and compared with 303 consecutive deliveries where anticoagulation was not administered. The overall rate of severe postpartum hemorrhage did not differ significantly for women treated with peripartum enoxaparin (4.2%) versus nonanticoagulated control individuals (2.0%, P = 0.40) nor for the subgroup of women who underwent vaginal delivery (3.6 versus 1.4%, P = 0.55) or cesarean section (5.1 versus 3.4%, P = 0.98). We did not observe any severe hemorrhagic events attributable to administration of postpartum enoxaparin. The first dose of enoxaparin was administered less than 24 h following delivery in 75% of vaginal deliveries and in 49% of cesarean sections where enoxaparin was given in the postpartum period. Two incisional hematomas were observed in the group of women who received enoxaparin within 24 h following cesarean section. Severe postpartum hemorrhage is an infrequent complication when enoxaparin is administered to hemostatically intact women between 5 and 24 h following a vaginal delivery or 12-36 h following cesarean section.