The aim of the study was to assess the results of treatment of adolescent idiopathic scoliosis (AIS) with the Providence nighttime brace at 1.8 years after discontinuation of bracing. A total of 36 consecutive female patients with an average Cobb angle of 28.4 degrees and an apex below T 10 were studied prospectively. For comparisons, 36 matched patients treated with the Boston full-time brace were studied retrospectively. With the Providence night brace an average of 92% for brace correction of the primary curve was achieved and during follow-up progression of the curve >5 degrees occurred in 27% of the patients. In the control group of the Boston full-time brace patients, brace correction was 50% and the progression of the major curve occurred in 22% of the patients. We conclude that the Providence night brace may be recommended for the treatment of AIS with curves less than 35 degrees in lumbar and thoracolumbar cases.