This study aims to investigate the effect of carbapenem restriction on the infection rate and antibiotic susceptibility. We divided the study period into two: carbapenem-free period (CFP) and carbapenem-restricted period (CRP). We compared the usage rate of antipseudomonal carbapenem, the incidence of nosocomial infection, invasive device days, the causative microorganisms, and antibiotic susceptibility. The nosocomial infection density was 40.95 +/- 19.02 in 1000 patient days in the CFP, and 20.71 +/- 4.28 in 1000 patient days in the CRP. We observed no significant difference between the two periods in terms of invasive devices use rates. Anti pseudomonal carbapenem usage rate was 2.73 in CFP and 1.67 in CRP. Of the 40 nosocomial infections due to Acinetobacter baumannii, 27 of them were found in the CFP. Carbapenem restriction policy may contribute to decrease the rate of resistant bacterial infections.