OBJECTIVE: To assess the role of neuroticism and low self-esteem as risk factors for eating disorders (ED). METHOD: A representative sample of girls 12-21 years old from Navarre, Spain. Girls free from any ED in 1997 were followed up for 18 months and reevaluated using DSM-IV criteria. Multivariable logistic models were used to examine associations between neuroticism (Eysenck Inventory) or low self-esteem (36-item scale) and incident ED. RESULTS: Higher levels of neurotic personality increased the risk of ED (adjusted odds ratio [OR] for the highest quartile, 3.3; 95% Cl; 1.6-4.8). High levels of self-esteem were protective (OR, 0.32; 95% CI, 0.16-0.66). Neuroticism was a more powerful predictor than low self-esteem. DISCUSSION: Our results provide prospective evidence supporting the role of neuroticism and low self-esteem as major determinants of ED.