Fifty patients with gastric leiomyosarcoma seen at M.D. Anderson Hospital between 1957 and 1978 were reviewed. Symptoms included weakness, gastrointestinal bleeding, and epigastric pain. An upper abdominal mass or tenderness was the most frequent physical finding. Laparotomy was performed in all patients, with gastric resection in 86%, and resection for cure in 68%. Survival after distal subtotal gastric resection (mean: 62 months) was longer than after proximal subtotal (30 months) or wedge resection (46 months). The five-year survival was 19% for all patients, and 32% for those operated on for cure. A favorable prognosis was predicted by mild atypia or few mitoses (grade 1). No differences in survival were demonstrated between patients with tumors of different cell types (epithelioid, spindle, or pleomorphic). No lymph node in any patient contained metastatic tumor, suggesting a lymph node dissection need not be performed. Commonly, tumor spread was to liver or lungs or by direct invasion of contiguous tissue or organ. Radiotherapy and chemotherapy are of limited value in treating unresectable disease. If possible, both the primary lesion and recurrent tumor should be widely resected.