A population-based approach was used to analyze the utilization patterns of hospital care by Manitoba residents during the fiscal year 1991/1992. Patterns were analyzed for eight administrative regions, with use assigned to the patient's region of residence, regardless of the location of the hospitalization. Regional boundaries consistent with those used for presentation of data on health status and socioeconomic risk permitted integration of findings across the Population Health Information System. Marked differences in acute hospital use were found. Residents of the urban Winnipeg ("good health") region had the lowest rates of use of acute care overall, and northern rural ("poor health") regions had significantly higher rates of use. However, almost one half of hospital days by Winnipeg residents were used in long-stay care (60+ days), while rural residents were more likely to use short-stay hospital care. Despite a concentration of surgical specialists in Winnipeg, there were only small regional differences in overall rates of surgery.