Background. In an ageing population, many individuals find themselves becoming a carer for an elderly relative. This qualitative study explores aspects of quality of life affected by caring for a person with dementia, with the aim of identifying whether capability based questionnaires are suitable for measuring carer quality of life. Methods. Semistructured interviews lasting up to an hour were conducted, November 2010–July 2011, with eight family carers of people with dementia. Interviews typically took place at the participants’ homes and were recorded and transcribed verbatim. Framework analysis was used to code and analyse data. Domains from three capability based questionnaires (ICECAP-O, Carer Experience Scale, and ASCOT) were used as initial codes. Similar codes were grouped into categories, and broader themes were developed from these categories. Results. Four themes were identified: social network and relationships; interactions with agencies; recognition of role; and time for oneself. Conclusions. By identifying what affects carers’ quality of life, an appropriate choice can be made when selecting instruments for future carer research. The themes identified had a high degree of overlap with the capability instruments, suggesting that the capabilities approach would be suitable for future research involving carers of people with dementia.