OBJECTIVE. The aim of this study was to test the hypothesis that screening for scoliosis is effective in reducing the need for surgical treatment. METHODS. The study was a case-control study. A total of 125 consecutive patients who were treated surgically for idiopathic scoliosis between January 2001 and October 2004 and who were born on or after January 1, 1984, were invited; 108 agreed to participate. A total of 216 control subjects were selected randomly and anonymously, matched with respect to age and gender. For 279 adolescents, exact screening exposure and outcomes could be analyzed. Case subjects were recruited from 4 university and 6 nonuniversity Dutch hospitals; control subjects were recruited from all 37 municipal health services in the Netherlands. RESULTS. Screen-detected patients received diagnoses at a significantly younger age than did otherwise-detected patients (10.8 +/- 2.6 vs 13.4 +/- 1.7 years). In total, 32.8% of the surgically treated patients had been screened between 11 and 14 years of age, compared with 43.4% of the control subjects. The odds ratio for being exposed to screening was 0.64. In total, 28% of the patients were diagnosed as having scoliosis before 11 years of age. CONCLUSIONS. Our results showed no evidence that screening for scoliosis reduced the need for surgery. Abolishing screening seems justified, especially because the effectiveness of early treatment with bracing is still strongly debated. A randomized, controlled trial on the effectiveness of treating patients with idiopathic scoliosis with bracing is urgently needed.