Nosocomial pneumonia is a common nosocomial infection and has high mortality rate. Risk factors of mortality of nosocomial pneumonia were studied in 132 hospitalised patients who developed nosocomial pneumonia. The overall mortality rate was 64/132, 48.5%. Of the 11 risk factors univariately associated with mortality due to nosocomial pneumonia, only the inappropriate initial anti-microbial therapy, high simplified acute physiology score and multiple organ failures remained significant after stepwise logistic regression. Gram-negative bacilli were still the most pre-dominant causative microbiologic agents of nosocomial pneumonia with Pseudomonas aeruginosa (20.3%), Acinetobacter baumannii (18.6%) and Escherichia coli (5.9%) being the three most predominant pathogens. A. baumannii were significantly more predominant among non-survivors than survivors (13.56 vs. 5.08%, p=0.0418). The incidence rate of methicillin-resistant Staphylococcus aureus was 19.5% higher than previous reports. We conclude that inappropriate initial anti-microbial therapy for nosocomial pneumonia is associated with the mortality rate of nosocomial pneumonia, and appropriate anti-microbial therapy improves outcome of nosocomial pneumonia.