Between 1978 and 1986, 179 patients with recurrent colorectal cancer were treated and 137 patients were operated a second time.82.1% of the patients showed elevated CEA levels (greater than or equal to 5 ng/ml) at the time of diagnosis. In 58.1% of the patients the CEA increase preceded the recognition of recurrence, and in 13.4% the diagnosis could be confirmed only by a second-look operation. In 46.7% of the re-operated patients a potentially curative resection of the locally recurrent or metastatic disease could be performed. The resectability was significantly lower in patients with symptomatic recurrent disease (34.5%) as compared to asymptomatic patients with CEA-directed positive imaging (52.7%) and the second-look patients (62.5%) respectively. A significant improvement in survival could be achieved especially in the second-look operated patients.