Although the current risks of viral transmission through blood components are very small, mistransfusion, in which the wrong blood is transfused to the wrong patient, remains the most common type of error in transfusion practice. Many studies have revealed that mistransfusion occurs resulting from failure to perform the final patient identification check at the bedside. Thus, pre-transfusion check at the bedside is the most critical step for the prevention of mistransfusion. An electronic identification system (EIS) is ideally suited to pre-transfusion check requirements. An experience at the Juntendo University Hospital showed that the bar code-based EIS works well on a hospital-wide basis in the setting of regular allogeneic blood transfusion, preoperative autologous blood donation and transfusion, pediatric transfusion, and hematopoietic progenitor cell infusion at the bedside. Approximately 110,000 blood components have been transfused over a 10.5-year period without a single mistransfusion. The overall compliance rate with electronic pre-transfusion check at the bedside was 98.2%. Human error was the most frequent cause of errors leading to failure of the ʻsecondʼ electronic pre-transfusion check. If we want to reduce the risk of mistransfusion to improve transfusion safety, we have to address the issue at the hospital level, with a system-based approach.