Thirteen patients with Duchenne's muscular dystrophy underwent spinal fusion and Harrington instrumentation between 1967 and 1979. Curve progression was the most common indication for surgery. Cardiorespiratory evaluation was most important in the timing of surgery. After 12 months of immobilization, all spines fused. Major and minor complications occurred in eight of 13 patients. The major benefit of surgery was improved or maintained sitting balance. Surgery is not recommended for patients with symptomatic cardiomyopathy, vital capacity less than 40%, a nonfunctional cough, or rapidly progressive deterioration in muscle strength with a projected life span of less than two years.