Methods: The study was conducted in a 22-bed medical ICU in a 640-bed tertiary care hospital from April to October 2006. Two hundred eighty one patients had nasal screening on ICU admission and weekly thereafter. The environmental surface samples were collected from 22 beds, bedside tables and medical appliances. From July to October 2006, contact precautions including gloving, use of disposable apron and mask were enforced aggressively to the MRSA carriers along with environmental decontamination. The following variables were collected: age, gender, severity score, length of stay, route of admission, previous hospitalization, underlying diseases, antibiotics use and invasive devices utilization. The effectiveness of the infection control program was assessed by prospective analysis of patient data including environmental data before and after the introduction of the program.