To assess the value of long-term clinical follow-up of patients after 'curative' colorectal resections, 114 such patients were studied. Of the 100 patients in whom full follow-up was possible, 38% suffered a recurrence and less than 25% of these were discovered at a routine outpatient attendance. No long-term cures were achieved as a result of treatment of any recurrence. Indefinite follow-up of all patients by simple clinical assessment in the outpatient clinic after colorectal resection appears to be of limited value. More intensive short-term follow-up of high-risk groups may provide a greater yield of treatable recurrences. Adoption of this policy should lead to improved efficiency for the hospital in terms of time saved in outpatient attendance and the concentration of resources on those most likely to benefit from follow-up.