There is uncertainty as to the proper management of a patient with chronic ulcerative colitis who has had his disease for over ten years but has not been sufficiently symptomatic to warrant colectomy. Not all patients are at high risk to develop cancer. Wide extent and long duration of disease are correlated with increased risk. The ability to define a patient at risk beyond these single criteria are very limited. The definition and efficacy of the precancerous lesion observed in rectal biopsies is still a matter of dispute, and the routine use of proctocolectomy for patients with long-standing colitis is still not universally accepted. Careful follow-up is obviously indicated, but it is still uncertain whether roentgenography, colonoscopy, colonic biopsy, or a combination of these methods will ultimately prove the procedure of choice.