Between 1969 and 1985, the British Columbia hospital system allocated an increasing proportion of the province's total hospital days to elderly patients who stayed for 60 days or more. By 1985/86, long stay patients accounted for almost 50% of all days. In this paper, we explore the diagnoses which contributed the greatest number of patient days of increase among the elderly as a first step in evaluating the appropriateness of this response to the pressures of an aging population. Patient days of increase were not distributed smoothly across a large number of diagnoses, but could be explained by a small number of chronic conditions. Most important were conditions related to senility and senile dementia, the chronic sequelae of heart disease and stroke, and persons awaiting admission to adequate facilities elsewhere. Eighty percent of the increases were seen in extended care and rehabilitation beds and 20% in acute care beds. Seventy-seven percent of the increased patient days were attributable to females and only 23% to males. Since the major sources of increase in patient days were not related to conditions for which new, effective hospital care modalities are available, they call into question the appropriateness of the system's response to the health care needs of the elderly population.