Up study of 76 severely ill females with anorexia nervosa who met specific diagnostic criteria and had participated in a well-documented hospital treatment study. Information was obtained on 100% of the subjects. A comprehensive assessment was made in 93% of the living subjects in specific categories of weight, eating and weight control behaviours, menstrual function, anorexic attitudes, and psychological, sexual, social and vocational adjustment. Five subjects had died, which gives a crude mortality rate of 6.6%. Standardized mortality rates demonstrated an almost 13-fold increase in mortality in the anorexia nervosa subjects. Only eighteen (23.7%) were fully recovered. Sixty-four per cent developed binge-eating at some time during their illness, 57% at least weekly. Twenty-nine (41 %) were still bulimic at follow-up. The high frequency and chronicity of the bulimic symptoms plus the high rate of weight relapse (42% during the first year after hospital treatment) suggest that intensive intervention is needed to help anorexics restore and maintain their weight within a normal range and to decrease abnormal eating and weight control behaviours. The clinical course and outcome of anorexia nervosa are nresented in a 10-vear follow.