Hospitalization expenses account for a high rate of national medical care expenditure in Japan. The Japanese national medical care expenditure was 42 trillion 364.4 billion yen in 2015, in which hospitalization expenses were 15 trillion 575.2 billion yen (36.8%). Therefore, it is necessary to take measures to reduce hospitalization expenses. The total ratio of the labor cost of physicians and nurses accounted for about 1/3 of all expenditures of general hospitals in 2015. Moreover, the personnel cost of nurses accounted for about 1/5 of all expenditure, showing that the personnel cost of nurses is an element with a large influence on hospital management. The objective of this study was to develop a methodology to reduce the overtime work of nurses accounting for a large rate of personnel expenses by focusing on overtime work, a personnel expense-increasing factor, aiming at hospital cost reduction. First, the cause of overtime work, planning, and recording by nurses were analyzed and an IT application increasing the quality and efficiency of the work was developed. Then, fees for the use and maintenance of the IT system meeting the following conditions were set as a strategy to introduce the system: (1) 50% reduction of the overtime work of nurses and (2) fees 50% or lower than the reduced payment for overtime work. This IT application was introduced to the heads and directors of nursing of 5 hospitals and the strategy was proposed. All heads and directors highly evaluated the system and responded to initiate the process for the introduction. It was suggested that the methodology to reduce the overtime work of nurses proposed by this study is useful and feasible.