Objective: The current study examined the roles of body image, ideal body weight, self-perception, and body mass index (BMI) on the dieting behavior of Turkish adolescents. Method: The 531 subjects who participated in the study ranged from 15 to 17 years old and were recruited from five selected high schools in Ankara. They completed the Self-Perception Profile for Adolescents (SPPA), the Body Image Satisfaction Questionnaire (BISQ), and the Dieting Status Measure (DiSM). Height and weight were measured. Results: Dieting adolescents received significantly lower scores than nondieters for most of the BISQ items and for the physical appearance and global self-worth subscales of the SPPA. A thinner body ideal, the physical appearance domain of self-concept, and low global self-worth were the predicting factors of frequent dieting. However, BMI and body image dissatisfaction were not predicting factors. Discussion: The results indicate that a thinner body ideal, low self-worth, and low physical self-concept have more significant effects on body dissatisfaction and dieting than being actually overweight does. Furthermore, high physical self-concept scores and body satisfaction may not necessarily preclude having a thinner body ideal and, hence, dieting in girls. (C) 2005 by Wiley Periodicals, Inc.