During the past 20 years, there has been a large increase in the number of hospitals with intensive care units (ICUs). To discover what services are provided to the growing number of ICU patients, we studied 624 consecutive admissions to a general surgical-medical ICU within a university hospital. We recorded the proportion of admissions and services involving intensive treatment as opposed to concentrated nursing care or monitoring. We found that for nearly half (49%) of the admissions and during two thirds (65%) of the nursing shifts, the emphasis was on close nursing care and observation, not intensive treatment. Of 252 patients admitted for monitoring, 216 (86%) never required active treatment before discharge. The average length of stay of these 216 patients was 2.1 days. If this distribution of services and admissions within one university hospital is also found at other institutions, it suggests that a substantial portion of ICU services may now be directed at monitoring stable, noncritically ill patients.