In this nation-wide register linkage study of the mortality among psychiatric in-patients with anorexia nervosa who were admitted between 1970 and 1986 (n= 853), 50 deaths were recorded during a mean follow-up period of 7.8 years (6680 person-years of observation). Among male subjects, five of 63 probands died, and the mean age at death was 24.5 years (range 14.2-48.1 years). Among female subjects, 45 of 790 probands died, and the mean age at death was 36 years (range 18.1-64.7 years). The standardized mortality ratio (SMR) was 9.1 in both sexes. A significantly increased SMR was demonstrated in males up to 5 years after index admission, and for females up to 15 years. There was no mortality among childhood-onset female subjects, but among males one death was recorded in this age group. In male subjects the highest SMR was found among those with index admission in the second decade of life, and in females among those with index admission in the third decade of life. The SMR was maximal during the first year after index admission. Suicide was the dominant cause of death among subjects who died from unnatural causes (18 of 22 cases). Among those who died from natural causes (24 subjects), 13 individuals died from anorexia nervosa and 11 individuals died from other illnesses.