Tele-home-care (or tele-medicine) is being implemented by the application of multimedia such as CATV and ISDN. In this paper, by focusing on the so-called “social hospitalization of the aged,” we carry out an estimation of the extent to which tele-home-care based on multimedia can help in saving the cost of hospitalization of the aged in the future. Estimation consists of the following two parts. First, we estimate the trends of the aged population and their hospital expenses using the regression analysis. Second, we assume that new technology such as multimedia and new medical instruments develop according to a logistic curve. Thus, we estimate the rate of diffusion of CATV and ISDN by logistic curves. Then, by multiplying this number by hospital costs per elderly patient as estimated previously, we have been able to calculate the extent to which hospitalization costs can be saved in the entire economy. Our results indicated that in the year 2050, US$257.3 billion, or nearly 7.4% of total hospitalization costs of the aged could be saved by tele-home-care.