Malignant tumors arising from venous walls in the lower extremity are uncommon. Histologically they are divided into two groups: hemangioendotheliomas of intermediate malignancy and leiomyosarcomas. This report describes a retrospective series of seven primary venous tumors observed in four men and three women with a mean age of 49.8 years (range: 18 to 64 years) who underwent surgical treatment between 1985 and 1995. The tumor was located in the superficial femoral vein in four patients, common femoral vein in two patients, and greater saphenous vein in one patient. A palpable tumor was present in five patients, localized pain in two patients, and metastasis in two patients. The histological diagnosis was leiomyosarcoma in six patients and hemangioendothelioma in one patient. Surgical treatment consisted of complete resection in six patients and partial excision in one patient. Venous reconstruction was performed in two patients and adjuvant radiation therapy in four patients. There was no operative morbidity/mortality. Median survival was 31 months. Four patients with leiomyosarcoma died from metastasis. Two patients with leiomyosarcoma and one with hemangioendothelioma are alive at 9 years, 16 months, and 9 months, respectively. Local recurrence was never observed after complete resection. The prognosis of venous leiomyosarcoma of the lower extremities is poor due to early occurrence of metastasis. Doppler ultrasound and MRI are useful to establish early diagnosis at the nontumoral stage. Improvement in the prognosis of leiomyosarcoma may justify perioperative chemotherapy before and after radical surgical excision.