The aim of the study was to investigate orthodontic treatment need and the outcome of orthodontic treatment in 15-, and 20-year-olds in Jönköping, Sweden, with special reference to residual treatment need. An offer to participate in a clinical investigation was extended to random samples of 130 15-year-olds and 130 20-year-olds. Ninety-six of the 15-year-olds (73.3%; 45 boys and 51 girls) and 82 of the 20-year-olds (62.6%; 47 males and 35 females) accepted and presented for examination The participants filled in a questionnaire and impressions were taken for study models, which were graded according to the ICON index. In all, 39 (40.6%) of the 15-year-olds and 38 (46.3%) of the 20-year-olds had undergone or were currently undergoing orthodontic treatment. Ninety-one per cent of the 15-year-olds and 84% of the 20-year-olds considered that the orthodontic treatment goals had been fully or almost fully attained. Two of the 15-year-olds and two of the 20-year-olds currently wanted orthodontic treatment. This indicates a residual treatment demand of about 2%.