Body dissatisfaction and dieting are risk factors for eating disorders. Understanding young people's views about factors underlying body dissatisfaction and dieting may be helpful for those designing preventative interventions. This study explored adolescents' views on causes of body dissatisfaction and dieting and recommendations for prevention. Four 1-h focus groups were conducted with 22 female adolescents (aged 13-15 years). Transcripts were explored using thematic analysis. Body dissatisfaction and dieting was explained by four themes: peer acceptance; social comparison online; pressure from family; and pressure from the media and fashion industries. There were seven areas of recommendation for prevention: building sources of support; learning to be critical of the media; monitoring the school gym; working with parents; educating about signs and symptoms of eating disorders; working with people who have suffered from eating disorders; and providing help from professionals. Implications of these findings for the development of prevention programmes are discussed.