Background/Aims Physical activity is effective in people with dementia. Most people with dementia live at home, but few home-based physical activity programmes have been developed. The aim of this protocol is to determine the feasibility, effectiveness and cost-effectiveness of the Lifestyle Integrated Functional Exercise for People with Dementia (LiFE4D). Methods A randomised, controlled trial will be implemented. The experimental group will receive LiFE4D and the control group will maintain usual treatment. LiFE4D is a 3-month programme adjusted to daily routines and involving carers, with decreased face-to-face contact over time. The primary outcome measure is exercise capacity assessed with the 2-Minute Step Test. Secondary outcomes include cognitive function, physical activity, health-related physical fitness, respiratory function, functionality, quality of life, carers' burden and costs. Results Findings from this study will improve knowledge and provide guidance on home-based physical activity for people with dementia. Conclusions If effective, the trial will provide a model of home-based physical activity and inform international guidelines for dementia care.