Four cases of tubular colonic duplication are reported and 53 more are reviewed from 1876-1981 literature. Eighty percent of these patients had other anomalies, most notably genital and bladder duplications. Females outnumbered the males 37 to 20. Fifty per cent of patients of either sex had some form of fistulous communication. In no one was the anomaly incompatible with life. Based on the anatomy of distal ends of duplicated colon, the patients are divided in five groups, for each of which the incidence and nature of concomitant anomalies are tabulated. Because of their anatomic complexity, most patients with colonic duplication require clinical evaluation by multiple subspecialists. We have also suggested the sequence and extent to which they should be evaluated by radiologists.