OBJECTIVES: Medication reconciliation is the process to review patients’ complete medication regiments at all the time of transitions of care and compare patients’ existing and previous medication with the regiments being considered for the new setting of care. The objective of this study is to implement medication reconciliation to reduce drug-therapy problems and errors, and to evaluate the financial impact of these approaches in Taiwan. METHODS: The criteria for cases recruiting in this study were patients staying in the academic medical center for more than three days. Nevertheless, the patients with cancer or admitted to the ICU were excluded. Pharmacists reviewed the patients’ admission charts and compared the patients’ medication regiments at present and past. Once the inconsistence medications were identified, pharmacists would discuss with the multispecialty team consisting of physicians, pharmacists and nurses to ensure if therapy should be adjusted. The determination of financial impact is expressed by cost avoidance per year in Taiwan. RESULTS: The data from the study suggests approximately 11.07 % of drug-related problems were identified and prevented by pharmacists through medication reconciliation. This can be translated into approximately 350,697 episodes per year in Taiwan (based on the assumption for total hospitalization of about 3,168,000 persons per year). The estimated cost avoidance will be as high as NT 1,941 million per year (based on the assumption for cost of prolonged length of hospital stay is about NT 5,000) through achieving the medication reconciliation at admission. CONCLUSIONS: This study demonstrated that the pharmacists' interventions were able to prevent potential adverse drug events, reconcile discrepancies among medications, and reduce medical expenditure as well. Effective assurance in medication safety is also achieved through the collaboration of multiple disciplines in patient care.