Seventy-five patients with adolescent kyphosis, treated with Boston lumbar or the modified Milwaukee orthosis, were reviewed. For compliant patients, the average improvement kyphosis was 27% in the Boston orthosis group and 35% in the Milwaukee orthosis group, despite the fact that the former group were younger and had smaller, more flexible curves. Compliance with orthosis wearing and, therefore, effective treatment was twice as likely with the Boston orthosis (61% compliance vs. 29% with the Milwaukee). Results in patients who wore their orthoses at least 16 hours per day were equal to results in patients with 23 hours of daily wear. In a small group of complaint patients with kyphotic deformities greater than 75, the Milwaukee orthosis was surprisingly effective. The Boston lumbar kyphosis offers a satisfactory alternative to the modified Milwaukee brace in adolescent kyphosis patients whose curves measure less than 70.degree., especially if satisfactory compliance with brace wear is suspect.