Multiple antibiotic resistance threatens successful treatment of Acinetobacter baumannii infections worldwide. Increasing interest in the well-known activity of sulbactam against the genus Acinetobacter has been aroused. The purpose of this study was to compare the outcomes for patients with Acinetobacter bacteremia treated with cefoperazone/sulbactam versus imipenem/cilastatin. Forty-seven patients with Acinetobacter baumannii bacteremia were analyzed through a retrospective review of their medical records for antibiotic therapy and clinical outcome. Thirty-five patients were treated with cefoperazone/sulbactam, and twelve patients with imipenem/cilastatin. The percentage of favorable response after 72 hours was not statistically different between cefoperazone/sulbactam group and imipenem/cilastatin group. The mortality rate was not statistically different, too. Cefoperazone/sulbactam was found to be as useful as imipenem/cilastatin for treating patients with Acinetobacter bacteremia.