Background: Informal, often family carers play a vital role in supporting people living with dementia in the community. With ageing populations, the part played by these carers is increasing making it important that we understand what motivates them to take on the role. This systematic review aimed to identify and synthesise qualitative literature describing what motivates people to care for someone with dementia.; Methods: The review followed the Centre for Reviews and Dissemination (CRD) guidelines. Six electronic databases were searched from their first records until August 2018. Synthesis was narrative.; Results: Twenty-six studies fitting the inclusion criteria were identified. Carers described multiple, inter-related motives for caring for someone with dementia. Caring was generally described as a reflection of long-standing family relationships between carers and the care recipients, whether by blood or marriage. Commonly offered motivations included love, reciprocity, filial piety, duty and obligation.; Conclusions: Perhaps the most striking finding was the similarity in these motivations irrespective of gender or relationship with the care recipient. Family relationship and shared history underlay most motivations. Future research should include more longitudinal studies incorporating within study comparisons between different demographic groups to give greater confidence in identifying similarities and differences between demographic groups.