Introduction:Medication errors have significant implications on patient safety. Error detection through an active management and effective reporting system discloses medication errors and encourages safe practices.Objectives:To improve patient safety through determining and reducing the major causes of medication errors (MEs), after applying tailored preventive strategies.Methodology:A pre-test, post-test study was conducted on all inpatients at a 177 bed hospital where all medication procedures in each ward were monitored by a clinical pharmacist. The patient files were reviewed, as well. Error reports were submitted to a hospital multidisciplinary committee to identify major causes of errors. Accordingly, corrective interventions that consisted of targeted training programs for nurses and physicians were conducted.Results:Medication errors were higher during ordering/prescription stage (38.1%), followed by administration phase (20.9%). About 45% of errors reached the patients: 43.5% were harmless and 1.4% harmful. 7.7% were potential errors and more than 47% could be prevented. After the intervention, error rates decreased from (6.7%) to (3.6%) (P≤0.001).Conclusion:The role of a ward based clinical pharmacist with a hospital multidisciplinary committee was effective in recognizing, designing and implementing tailored interventions for reduction of medication errors. A systematic approach is urgently needed to decrease organizational susceptibility to errors, through providing required resources to monitor, analyze and implement effective interventions.