This study is about the relation between self-efficacy expectations and the attitude towards child and youth obesity, as well as the role of the school in this matter. A questionnaire was given to a sample of 436 trainee physical education teachers from eight universities in Andalusia (Spain). The questionnaire was a version of "Teaching Self-Efficacy in Higher Education" (Prieto, 2007) and of "Perceptions of Youth Obesity among Physical Educators" (Greenleaf and Weiller, 2005). The results indicated that those trainees who possessed a higher level of perceived self-efficacy for the assessment of not only their own teaching, but also of the knowledge acquired by overweight students and of school intervention in their learning process, tended to show more favourable attitudes towards the educational treatment of child and youth obesity, and towards obese students' fitness and healthcare. The trainees with a perceived higher level of self-efficacy for the assessment of the progress made by overweight students and with a more favourable disposition towards revising their teaching practice tended to show a more negative attitude towards obese people. (Contains 4 tables and 1 figure.)