Submucosal injection of Lipiodol-bleomycin (BLM) for esophageal cancer is complementary to CT scan in preoperative determination of the depth of the cancerous invasion in the esophageal wall. This procedure was performed not only for diagnosis but also as a preoperative therapy in 109 cases with esophageal cancer in Hiroshima University Hospital. The Lipiodol-BLM suspension was prepared by mixing 45 mg BLM and 5 ml Lipiodol on a clean bench. The mixture was usually injected into the submucosal layer of the esophagus using fiberscopy 12 days before the operation. BLM concentration was measured in the primary tumor, normal esophageal tissue around the tumor and regional lymph nodes in the specimen in 14 cases. As a result, a low level of BLM had been maintained in these tissues for a long time. The concentration of the primary tumor was 4 times higher than that of the normal esophageal tissue. In order to predict the side effects of BLM, such as pulmonary fibrosis, the change in serum BLM level was measured in 12 cases. Serum BLM decreased to an unmeasurable level 24 hours after the injection. Thus, the submucosal injection of lipiodol-BLM for esophageal cancer seems to be promising for a targeting cancer chemotherapy.