OBJECTIVES: Medical costs followed by incidents within hospitals are not linked with primary diseases and might be paid by hospitals. In that manner, it is very important for hospital managers to recognize the actual situation of medical costs for incidents. Cases injured with over the level two and their medical costs for a year are explored. METHODS: There are 2,866 incident reports in 2007 collected at Saint Mary’s Hospital in Kurume-City, Fukuoka, Japan. Their reports include 734 cases for Falls/Slips and 2,132 cases for others. The cases for Falls/Slips are classified 474 with level 1, 320 with level 2, and 136 with level 3a, and 14 with level 3b, respectively. Of the 14 cases with level 3a included three femoral neck fractures and femoral trochanteric fractures each, and one femoral shaft fracture, facial fracture, clavicle fracture,  shoulder fracture, upper extremity fracture, lower extremity fracture, thoracic vertebral fracture, and traumatic subarachnoid hemorrhage,each. RESULTS: According to the injury level, average medical costs are 88 dollars (level 2, 59 cases), 94 dollars (level 3a, 86 cases), and 12,330 dollars (level 3b, 14 cases). Medical costs with level 2 and 3a are directly calculated from the medical fee schedule under the social insurance system. By contrast, medical costs with level 3b are alternated by the average medical fee of the same diseases at the hospital, because we can not separate medical costs for injury by incidents and for primary diseases. For example, averaged medical cost for femoral neck fracture is 18,400 dollars by calculating 182 cases with same diseases were treated at our hospital. CONCLUSIONS: Total amount of medical costs for Falls/Slips is about 19 million dollars at our hospital for the year of 2007. Therefore, Hospital administrators have to take appropriate measures to prevent patients from Falls/Slips and save money, because this amount is not overlooked.