The purpose of this study is to suggest implications from the case of health information service for patients in overseas hospital libraries. A total of 89 overseas hospital libraries were selected, including general hospitals, specialized hospitals, women’s hospitals, children’s hospitals, and veterans’ hospitals. The health information service that is provided in general and common in 89 hospital libraries was surveyed and the differentiated health information service was investigated next. As a result, first, it can be seen that the establishment of hospital libraries and the provision of health information services are common outside of Korea. Second, various human resources such as librarians, health information specialists, medical specialists, social workers, clinical librarians, health education specialists, and volunteers are utilized. Third, it provides not only print materials but also various information sources such as electronic materials, websites, pamphlets, brochures, and provides health information in various languages. Fourth, in providing health (information literacy) education and programs, services are provided through linkage with hospitals, local public libraries, and local communities. The implications for domestic hospital libraries are as follows: First, the change of awareness of the establishment of hospital libraries and the provision of health information services; second, the support of the curriculum and associations and the need for continuing education; third, it is necessary to link with related organizations for mandatory and diversification of health information services in hospital libraries.