To evaluate the long-term mortality and morbidity of critically ill elderly patients requiring intensive care. Prospective comparison of outcome of critically ill patients aged 75 years and older with patients aged 65 to 74 years. Critically ill patients aged 65 years and older who required intensive care and who were recruited during a 3-month period. Duration of hospitalization, hospital charges, procedures used in the intensive care unit, mortality in the hospital and during the follow-up period, and quality of life of survivors during the follow-up period. Ninety-seven patients were included in the study; 54 were 75 years or older and 43 were aged 65 to 74 years. No significant difference was noted between the two groups for length of stay in the hospital, hospital charges, or mortality at 1 year. Severity of illness, as assessed by Acute Physiology and Chronic Health Evaluation score at the time of intensive care unit admission, was a better predictor of survival than age. Quality of life, as assessed by activities of daily living, perceived quality of life, and Center for Epidemiologic Studies-Depression score, were not significantly different in either group at 1, 6, and 12 months after discharge from the hospital. Most patients in both groups described their quality of life as adequate and were willing to receive intensive care again, if necessary. Age alone is not an adequate predictor of long-term survival and quality of life in critically ill elderly patients.