A desmoid tumor is a fibroblastic proliferation arising in musculoaponeurotic structures. The pathogenesis is still not clear. A 79-year-old woman who developed a desmoid tumor in the left lower abdomen after surgical resection of an abdominal lipoma seven years previously is presented. Preoperative computed tomography showed a large left lower abdominal mass. Pathology showed the spindle fibroblastic cell pattern typical of desmoids.