The ageing population is a powerful and transformative demographic force. The World Health Organization (WHO) has encouraged the development of an age-friendly hospital (AFH) network. However, no specific implementation strategies or best practices of AFH standards have been produced. This study sought to apply Kotter’s change model to the elements included in a successful AFH certification process and to evaluate the changes in employees’ knowledge of ageing and their attitudes toward the elderly. This was an observational study that utilized a pre- and posttest design, before and after an age-friendly hospital certification process was implemented. Participants were 163 hospital employees in Taiwan, who completed both pre- and postquestionnaires. The self-administered online questionnaire consisted of three sections: The Facts on Ageing Quiz, the Geriatric Attitudes Scale, and a demographic questionnaire. Following introduction of the intervention, the change process began, and later Kotter’s model was brought in as a descriptive framework. The results showed that Kotter’s eight-step framework is a good choice for thinking about how to change practice and make healthcare more age-friendly. Employee knowledge of ageing and their attitudes toward the elderly improved after this certification process. Appointing a chief executive officer, forming a steering committee, obtaining interdepartmental and interdisciplinary cooperation, and “soliciting support” for new policies from all employees, were identified as key factors influencing the success of age-friendly hospital (AFH) certification. This is the first study to apply Kotter’s eight-step framework of organizational change to an AFH certification process.