We conducted a prospective survey of the utilization of venous thromboembolism (VTE) prophylaxis in 152 Medical ICU (MICU) patients. Utilization of prophylaxis was recorded daily, and commonly accepted risk factors for VTE were noted. Only 32.9 percent of patients received prophylaxis, and there was a delay of 2.0±2.8 days prior to institution. Eighty-seven percent of patients had one VTE risk factor and 52 percent had multiple factors. We conclude that utilization of prophylaxis is low in MICU patients even though they are at high risk for VTE.