Purpose: The effects of a multicomponent dyadic intervention on the mood, behavior, and physical health of people with dementia living in the community were evaluated in a randomized controlled trial. This multicomponent dyadic intervention is a translated and adapted version of an intervention that has been shown to be effective for people with dementia in the US. Patients and methods: People with dementia living in the community and their family caregivers (N=111 caregiver-care recipient dyads) were randomly assigned to the intervention and comparison group. The intervention group received home-based physical exercise training, psycho-education, communication skills training, and pleasant activities training during 3 months directed at both the person with dementia and the caregiver. Mood, behavior, and physical health were measured at baseline, 3 months, and 6 months. The effects of the study were determined by using generalized estimating equations based on an intention-to-treat analysis. Results: Analyses showed no beneficial effects over time on any of the outcome measures. Conclusion: This study showed no effects. The negative results in this study compared to the study that has been carried out in the US might be explained by the translation, adaptation, and shortening of the intervention used in the US, and a different social context. In addition, the results might be explained by the lack of room for improvement and by experiencing the intervention as too much of a burden. Furthermore, improving physical health might only be effective if the physical exercises are of moderate-to-high-intensity and are tailored in accordance with participants' preferences and needs. For future studies, because dyads often commented positively about the pleasure and support they received, it might also be valuable to measure quality of life outcomes such as relationship quality, pleasure, and self-esteem in dyadic focused interventions.