Background: The discovery of carbapenems was a breakthrough in infectious disease therapeutics, due to their broad-spectrum of activity against many gram-positive, gram- negative, aerobic and anaerobic bacteria in addition to their stability against β-lactamase. They are considered "last-line agents" or "antibiotics of last resort"; for many complicated and life-threatening bacterial infections. However, the heavy and inappropriate use of carbapenem has led to the emergence of several resistant pathogens, especially among gram negative bacteria and consequently an increase in health care costs and patient morbidity and mortality. Drug utilization evaluation studies are one of the recommended strategies to control resistance and improve prescribing practices. Aim: The aim of this study was to evaluate the use of meropenem in terms of indication and continuation of treatment and to compare the appropriateness of use among patients with hospital-acquired infection (HAI) and community-acquired infection (CAI) at Sultan Qaboos University Hospital (SQUH). Method: A retrospective observational study, was conducted by reviewing the medical records of 400 admitted adult patients who received at least one dose of meropenem during the study period (January 2017 to September 2017). The appropriateness of empiric and non-empiric use of meropenem was assessed according to specific meropenem- use criteria that were developed from pre-specified, literature-based criteria and modified by an expert panel of Infectious Diseases specialist at SQUH to fit the local practice. Analysis was performed using univariate statistics. Results: Meropenem was prescribed empirically in 94% of the cases. The majority (87%) of the patients received the proper meropenem dose. The indication for meropenem was considered appropriate in only 49% of the cases. The continuation of treatment was evaluated according to culture and sensitivity results in 202 cases, out of which 55% were justified. Most of the inappropriate uses were seen in oncology and hematology units (74% and 60%, respectively) and among respiratory and urinary tract infections (15% and 13%, respectively). The use of meropenem was significantly more appropriate in HAI than in CAI, (61% vs. 44%; p=0.001) with regards to indication and (75% vs. 45%; p<0.001) with regards to continuation of treatment. Conclusion: Approximately half of the meropenem orders at SQUH were inappropriate and unjustified by culture-test result. Both restrictive and educative strategies are needed to optimize the rational use of meropenem and to ensure appropriate de- escalation and discontinuation of meropenem whenever indicated.