Multidrug resistance (MDR) in Gram-negative bacteria is on the rise, but its effect on patient outcomes is not well established. The outcomes of 129 adult surgical intensive care unit (SICU) patients treated for Gram-negative pneumonia were evaluated in relation to demographics, bacterial etiology, and infections due to MDR bacteria (defined as resistant to all agents except for aminoglycosides and polymyxins). The mean (SD) age and acute physiology and chronic health evaluation (APACHE) II scores were 63.8 (14.6) years and 20.8 (8.2), respectively. Forty-one patients (31.8%) were infected with MDR bacteria. Infection-attributed mortality was associated with baseline APACHE II scores (odds ratio [OR] 1.093; 95% confidence interval [CI] 1.029-1.162), MDR (OR 4.628; 95% CI 1.533-13.973), and infection with Stenotrophomonas maltophilia (OR 13.465; 95% CI 2.896-62.614). In SICU patients with Gram-negative pneumonia, MDR was associated with a higher rate of infection-attributed mortality, after adjusting for the severity of illness. Our results warrant further investigations with a prospective study.