Background:: Previous research shows that museum programs can be beneficial for the quality of life of people with dementia. This study evaluated the implementation of “Unforgettable,” an interactive museum program for people with dementia and their caregivers in the Netherlands, and investigated the impact of the program's implementation on the museums as an organization and on the attitudes toward dementia of the museum staff. Method:: Semi-structured interviews were held with 23 stakeholders to identify facilitators and barriers to the implementation of the Unforgettable program in 12 Dutch museums. Based on the model of Meiland et al. (2004), an overview is made of factors influencing the different levels and phases of the implementation process. The impact of Unforgettable on the attitudes of the museum staff was assessed using the Approaches to Dementia Questionnaire (n = 176). Results:: The training in the Unforgettable method, regular evaluation with the program guides and hosts, and cooperation with other organizations appeared essential for successful implementation of Unforgettable. A lack of promotional activities was an impeding factor. Compared to before the implementation, the museum employees’ attitudes toward people with dementia became more positive. Conclusion:: Both successful dissemination of the Unforgettable program and the more positive attitudes toward dementia of employees in museums implementing this program can contribute to the social participation of people with dementia and thereby to their quality of life.