Carer Peer Support Workers (CPSWs) are people who have lived experience as carers/family members of persons with a mental illness, and are employed to provide support to other carers/family members. This qualitative study aimed to explore carers' experiences within a community-based CPSW pilot program in an Australian mental health service. Semi-structured phone interviews were conducted with 20 carer participants in 2015, 5-10 months following their last contact with the service. Thematic analysis uncovered that carers were generally positive about the CPSW's emotional support, practical support, shared lived experience and mutual understanding, and the "ripple effect" the support had on service users. Some carers, on the other hand, felt that the support was unnecessary; either because they believed that it did not have a lasting effect, the focus should have been on the service user, or that they had previously received enough support. Nevertheless, the study highlighted how mental health services could best utilise and benefit from CPSWs. Moreover, to be most useful, the nature of the carer peer support work should be tailored to the specific needs of the carers; which may vary according to their culture, years of caring experience, and previous experiences with mental health services.