Does scoliosis associated with Friedreich's ataxia behave like an idiopathic or a typical neuromuscular scoliosis? Should it be treated like an idiopathic or a neuromuscular curve? Since no precise information to answer these questions could be found in the orthopaedic literature, a retrospective study was undertaken of seventy-eight patients with Friedreich's ataxia who had been followed at our neuromuscular clinic. Fifty-six of these patients were found to have typical Friedreich's ataxia in accordance with the criteria of Geoffroy et al., and their cases were retained for analysis. Their mean age was twenty years (range, eight to thirty-three years). The average length of clinical follow-up was nine years and the average duration of radiographic follow-up of the scoliosis was 3.5 years. A scoliosis of more than 10 degrees was found in all patients and was associated with a hyperkyphosis in 66 per cent. Both sexes were equally affected. Fifty-seven per cent of the curves were double thoracic and lumbar; 14 per cent were thoracolumbar; 7 per cent, double thoracic and thoracolumbar; 7 per cent, thoracic; 4 per cent, lumbar; and 11 per cent, multiple small curves. Of the fifty-six patients whose cases were studied, thirty-six had been followed for at least ten years. Among these thirty-six, there were twenty whose curves were more than 60 degrees and progressed (Group I) and sixteen whose curves were 40 degrees or less and did not progress (Group II).(ABSTRACT TRUNCATED AT 250 WORDS)