On the 14.429 patients admitted into the mental hospitals in 1973 0.8% had been readmitted 5 or mores times till the end of 1976. This frequently readmitted group of patients differed from the total admission-cohort in sex (more men than women) and age (overrepresentation of men in the age 25-44 and women in the age 45-54, and few elderly patients). Addiction-problems formed a special feature of this readmission-group. At their latest readmission more than half of the men were primarily diagnosed as addicts (mainly alcoholic). The younger men and the older women of the readmission-group were more often divorced at the primary admission than the patients of the admission-cohort. But also 33% of the men and 16% of the women who where married at the primary admission, were divorced at the last readmission before the end of 1976. Although no differences had been found between the sexes in the mean number of readmissions, the women had in general stayed in hospital for a longer period. 73% of the women, but only 36% of the men had been admitted to the same hospital.