The records of 525 patients with adenocarcinoma of the colon and rectum were reviewed. Two hundred and eighty-five patients were evaluable following complete curative resections. These patients were evaluated for patterns of recurrence. The over-all recurrence rate was 78 of 285, 27 per cent. The over-all recurrence rate by site was 24.0, 10.0, 11.5 and 35.0 per cent for the right, transverse and left colon, the sigmoid and the rectum, respectively. The over-all failure rate by stage was 13 per cent for Stage A, 11 per cent for Stage B1, 32 per cent for Stage C1, 37 per cent for Stage B2-3 and 56 per cent for Stage C2-3. The over-all failure rate as related to Stages A, B1, C1, B2-3 and C2-3 and to site of primary disease was: right--zero, 9, 33, 28 and 43 per cent, sigmoid--11, 15, 40, 52 and 62 per cent; rectal group--29, 14, 40, 46 and 60 per cent as related to respective stages. There was one failure among the five patients with Stage B2-3 disease in the transverse group and two failures among the nine patients with Stage B2-3 and one failure in the one patient with Stage C2-3 within the left colon group. Individual types of failure were compiled. Lesions involving the rectum and sigmoid colon had a significant local-regional component to relapse. Tumors of the right, transverse and the left colon had a significant distant recurrence rate. Factors of primary site, age at diagnosis, extent of disease and histology were reviewed as to the over-all recurrence and specific failure sites. From this analysis, a schema involving patterns of failure as related to primary site and stage within the colon, rectum and sigmoid were developed.