OBJECTIVES: To evaluate expensive and broad-spectrum antimicrobials usage in Songkhla hospital. METHODS: A prospective, chart review was performed on all inpatients initiated with Levofloxacin, Meropenem, Imipenem/ Cilastatin, Piperacillin/ Tazobactam and Cefoperazone/ Sulbactam  from March to December 2010. Pharmacist interventions were made when medication use evaluation (MUE) criterias were not met and/or drug related problems (DRPs) were detected. RESULTS:  Overall, 347 patients received 412 courses with these antibiotics. Percentage of empiric therapy was 80 % and specific therapy was 20 %.  Pneumonia and sepsis/septic shock were leading indications of these antibiotic uses. Cefoperazone/Sulbactam was the most frequently used. The appropriate use of Levofloxacin, Meropenem, Imipenem/Cilastatin, Piperacilin/Tazobactam and Cefoperazone/Sulbactam was 46%, 40%, 46% 70% and 53% respectively. No indication and incorrect drug dosage especially in patients with renal impairment were the most common misuse of these antibiotics.  Acceptance of interventions from physician was 86% (25/29). The cost of inappropriate use of these antibiotics was 28,789 USD. CONCLUSIONS:  MUE program should be continuously performed for effective use of antibacterial drug, safety and most benefit.