The present study is an investigation into the risk factors and natural history of full and partial syndrome eating disorders in a sample of 394 16-year-old female students. We used a two-stage procedure (screening and clinical interviews) and the same procedure was repeated after a 1-year follow-up. A stepwise multiple regression analysis showed that drive for thinness and tendency towards somatization are associated with an increased risk of later developing an eating disorder. Use of hypocaloric diets and a desire to be thinner characterized those asymptomatic subjects who were later to develop a partial syndrome. Perfectionism appeared to be a maintenance factor for subjects who presented a full or partial eating disorder at baseline.