Purpose: This study was conducted to compare the postural habits, body image, and peer attachment of adolescents with idiopathic scoliosis and healthy adolescents, and to examine the correlation between body image and peer attachment in each group. Methods: Eighty-three adolescents with idiopathic scoliosis and 83 healthy adolescents were recruited from 4 middle schools located in W city. Data were collected from November 22 to December 6 2010 using a structured questionnaire including items about postural habits, body image, and peer attachment. Data were analyzed using descriptive statistics, $X^2$-test, independent t-test and Pearson Correlation Coefficient. Results: Compared to healthy adolescents, adolescents with idiopathic scoliosis were more likely to use one hand, to lean back while seated, and to put weight on one leg while standing. The score for body image was significantly lower for adolescents with idiopathic scoliosis compared to healthy adolescents, but peer attachment was not significantly different between the two groups. Body image was significantly correlated with peer attachment only for the adolescents with idiopathic scoliosis. Conclusion: Interventions to promote balanced postural habits in adolescents with idiopathic scoliosis are needed. Information on body image and peer attachment for these adolescents should also be considered when developing interventions.