Deep vein thrombosis (DVT) of the lower extremity during pregnancy is infrequent, but its complication, pulmonary embolism, remains an important cause of maternal mortality. To evaluate the best method of caring for patients with DVT, we reviewed the records of patients at the Charleston Area Medical Center from 1987-1992 who were treated for this condition. Twelve patients were treated with conventional continuous intravenous heparin for 7 days-10 days followed by subcutaneous heparin until 6 weeks-8 weeks after delivery. The other group consisted of nine patients who were treated with lower dose subcutaneous heparin for 7 days-10 days and maintained as the first group, but a Greenfield filter was inserted for patients with iliofemoral DVT. The patients who received low-dose heparin and Greenfield filters tended to do better than those who received high-dose conventional heparin treatment. However, since there were so few patients evaluated, further verification is needed.