The ideal preparation of the intestine prior to elective colonic resection has been a controversial subject. With the development of new and more effective antibiotics, many modalities of intestinal preparation preoperatively have been used in an effort to reduce the number of infectious complications. Mechanical cleansing of the intestine, when accompanied by perioperative parenteral antibiotics, is adequate preparation prior to resection of the intestine. One hundred consecutive operations upon the colon by one surgeon were the subject of this retrospective study. Approximately 70 per cent of the operations were for carcinoma and the remainder for inflammatory disease. Preparation consisted of the administration of cathartics and saline solution enemas combined with a liquid diet for 48 hours prior to operation. Perioperative parenteral antibiotic therapy was given for 48 to 72 hours or as long as intravenous fluids were administered. All anastomoses were the open, two layer type, using nonabsorbable suture material. All abdominal incisions were closed primarily. There were no operative deaths, anastomotic leaks, intra-abdominal abscesses or fistulas. There were six instances of wound infection. Our results with this type of management compare favorably with those of other surgeons using various modes of preoperative oral antibiotic therapy and suggest that oral preoperative antibiotic therapy may not be necessary in elective operations on the colon.