There is a paucity of literature with regard to the need for intensive care treatment of critically ill obstetric patients. In this review, the findings from 20 obstetric patients admitted to a medical ICU (MICU) over a 40-month period were analyzed. Demographics, preexistent medical problems, diagnoses, days in the hospital and the MICU, need for mechanical ventilation, maternal and fetal mortality, and invasive procedures were reviewed. (For comparison, a limited analysis of nonobstetric admissions to the MICU over the same time period were included.) Fifty percent (10) of the patients had preexisting medical problems. Maternal mortality was 20 percent (4 patients), with a fetal mortality of 35 percent (7). In all of the maternal deaths, adult respiratory distress syndrome was present. Although mortality and the need for mechanical ventilation did not differ between the obstetric and nonobstetric patients, pulmonary artery and arterial catheters were placed at a higher rate in the obstetric patients. Critically ill obstetric patients, although younger than general MICU patients, appear to have as great a risk of dying of their critical illness and have a high infant mortality.