Abstract: Objective: To evaluate the resource use and costs in a surgical intensive care unit （SICU） with the Therapeutic Intervention Scoring System （TISS）. Methods: Prospective observation were carried in consecutive patients with an ICU length of stay（ICU LOS） more than 24 hours. Patients were retrospectively classified as receiving active treatment（AT） or non-active treatment（NAT） according to the TISS variables, where AT mean therapeutic intervention that could not performed outside the ICU. Total expenditure for each patient was calculated. Results: of the 148 consecutive patients within this pariod,131 （88.5%）, including non-survivors, were categorized as group in AT. TISS and LCU LOS were higher in patients receiving AT （P＜0.01）. Daily costs of the group AT were much higher than in the there of NAT patients （P＜0.01）. Conclusions: Total and daily costs of care were significantly higher in those receiving AT and in the ICU LOS. Therefore the cost-saving stratey should aim at reducing the ICU LOS, without compromising the quality of admittion.