Survival, functional status and total six-month medical care costs were measured for 489 consecutive medical intensive care patients. In addition, the study sought to determine if it was possible from data available on admission to identify subgroups of patients with extremely low survival rates. Of the study patients, 86 per cent survived the initial admission, and 72 per cent survived six months. Daily intensive care unit (ICU) charges averaged $1,120 per patient, while total six-month charges per patient averaged $14,577. Age, initial systolic blood pressure, preadmission functional status and diagnosis were all significantly and independently associated with survival. The subgroup with the lowest six-month survival rate (14 per cent) comprised cancer patients with poor preadmission functional status. This study did not identify a subgroup of patients with a survival rate low enough to justify systematic exclusion from intensive care. Controlling ICU costs by excluding patients with very low expected survival may not be possible.