With ageing populations and greater reliance on the voluntary sector, the number of volunteer-led peer support and befriending services for carers of people with dementia in England is set to increase. However, little is known about the experiences of the volunteers who deliver these interventions, many of whom are former carers. Using in-depth semi-structured interviews with 10 volunteer peer supporters and befrienders, this exploratory study investigated volunteers' experiences of delivering the support, the types of relationships they form with carers and their perceptions of its impact upon them and on carers. Data were analysed using framework analysis. Findings showed that volunteers benefitted from their role due to the 'two-way' flow of support. Experiential similarity and having common interests with carers were considered important to the development of mutually beneficial relationships. Volunteers perceived that carers gained emotional and social support, which in turn improved the carers' coping ability. Being able to see positive changes to carers' lives was important for volunteers to gain enjoyment and satisfaction from their role. However, volunteers also identified challenges with their role, such as dealing with carers' emotions. Future research should investigate ways of reducing potential burden on volunteers and explore the impact of volunteering specifically on former carers of people with dementia.