The aim of this study was to examine the relationships among physical self-perception, body image and motor performance in Italian middle school students. Two hundred and sixty children were categorized into normal-weight (n=103), overweight (n=86) or obese (n=71) groups. Perceived coordination, body fat and sports competence were assessed using the Physical Self-Description Questionnaire, while body image was measured using Collins' Child Figure Drawings. Individuals' perceptions of strength, speed and agility were assessed using the Perceived Physical Ability Scale. Tests involving the standing long jump, 2 kg medicine-ball throw, 10 × 5 m shuttle-run and 20 and 30 m sprints were also administered. Girls, when compared with boys, and overweight and obese participants, when compared with normal-weight peers, reported lower perceived and actual physical competence, higher perceived body fat and greater body dissatisfaction. Body dissatisfaction mediated all the associations between body mass index (BMI) and the different aspects of physical self-perception in boys, but not in girls. The same pattern of results was found for physical self-perception as a mediator of the relationship between BMI and body dissatisfaction. In conclusion, obesity proved to have adverse effects on both motor performance and physical self-perception.