Medical accidents have potentially included many cases associated with medical instruments as one of background factors. Aiming to keep personnel’s awareness on medical safety as one of hospital management and administration schemes, we explored and statistically analyzed two grounds of medical accident reports from the viewpoint of the safety management supervisor on medical instruments. One was contexts of reported accidents related to medical instruments in our hospital. And the other ground was varied medical incidents and accidents independent on medical instruments from Japanese open database. In our hospital, 10.8% accidents were associated with medical instruments and most of these were use failures of medical instruments. Analyzing the open database, we found that numbers of accidents related to medical instruments were linearly correlated with total numbers of medical accidents. Considering these results, risk management about medical instruments based on the accident reporting system would be important for continuously improving and maintaining quality of medical care.