We reviewed the clinical charts and roentgenogram of 111 patients operated with Harrington-DTT instrumentation for idiopathic adolescent scoliosis at Copenhagen University Hospital from 1983 to 1989. Male/female ratio was 1:9. Median age was 14.5 (11-21) years at the time of surgery. Median follow-up time was 4.0 (1-7) years. Of the 111 patients, complications were registered in fifteen. Seven were reoperated, four due to gliding of the upper hook, three due to fatigue fracture of the Harrington rod before union. We found no deep infections or persisting neurological damage.