In 18 patients with the inflammatory complications of colonic cancer before and after the operation, kanamycin, or one of the antibiotics of a cephalosporin group was administered into the lymphatic vessels of the upper third of a thigh at a daily dose of 20-25 mg/kg of body weight. After 3-4 days, the state of the patients considerably improved. All the patients underwent radical operations with primary restoration of intestinal continuity. There were no progression of purulent complications, postoperative lethality.