The expressions of some growth factors have been immunohistochemically confirmed in several kinds of tumors, and in particular the expression of vascular endothelial growth factor (VEGF) has been reported to be closely related to tumor cell proliferation. We report herein a case of undifferentiated spindle-cell sarcoma arising in the chest wall with VEGF expression. A 67-year-old man, who presented with coughing, was found to have an abnormal shadow on his right chest wall. He was admitted to Chiba Rosai Hospital and preoperative diagnosis of the tumor was sarcoma. The tumor was thus resected along with the right chest wall and right lower lobe of the lung. Histopathologically, the tumor cells were spindle-shaped and showed severe atypism. The tumor cells were positive for vimentin and VEGF antibody with immunohistochemical staining, but they did not show differentiation to any special type of sarcoma. The tumor was diagnosed to be undifferentiated spindle-cell sarcoma. The microvessel density of the tumor was measured using CD34 and it was found to be higher than the average density of usual sarcomas. The prognosis of this case was poor. The patient died of tumor metastasis to the lung and bone 1 year later in spite of the fact that the tumor was resected.