The aim of this investigation was to construct three parameters and assess their value as admission criteria for long-term institutional care of the aged, viz. medical dependence, nursing dependence, and dementia. The material consisted of 200 applicants, of whom 150 were admitted to institutions. The need for personal care was measured by means of a test method developed at the Wasa Hospital, Gothenburg, Sweden, and the dementia test comprised five subtests, each of which measures a distinct field of mental function. Both dementia and nursing dependence were found to increase with age, and there was a highly significant correlation between nursing dependence and age. There was also a highly significant correlation between nursing dependence and degree of dementia. The changes in nursing dependence 3 and 6 months after admission showed a significant correlation with the test scores for dementia. The nursing dependence of the moderately or severely demented persons had increased in 6 months after admission by approximately 100%. The test results of dementia were used as the sole, decisive criterion in 24% of admissions; medical dependence alone decided the choice of institution in 22% and nursing dependence in 15%. Two or three parameters were used in 39% of admissions--all indicating the same type of institutional care. The simultaneous use of the three assessment criteria provides an extensive body of information as to the general need of care, and by means of this information the appropriate placement of the old will be made possible.