A series of 186 patients with Crohn's disease treated during the period 1956--1968 was followed up. During the follow-up period about 95% of the patients had undergone resection or by-pass surgery. The patients operated on between 1956--1968 were followed up with reference to recurrence rate. The mean observation time was 10.5 years. The recurrence rate after resection was 51%. "Radical" resection gave 29% recurrences. "Non-radical" resection gave 84% recurrences. Patients who had undergone a primary "radical" resection needed fewer re-operations, had fewer recurrences and a better "quality of life" than patients with a "non-radical" first operation. The total mortality in operations or due to complications of Crohn's disease in the series was 5.4%. The mortality in connection with operations was 3.4%. The general health of the patients examined in 1975 (165 patients) was estimated; 87% were in very good general health, 9.1% had moderate subjective symptoms, and 3.6% had pronounced subjective symptoms.