Carers of autistic adults may experience increased day-to-day stress relating to their caring role. This review aims to (1) summarise the current literature on factors that affect mental well-being in carers of autistic adults and (2) map these results to an existing conceptual model of carer psychological well-being for individuals with developmental disabilities. Twenty-three studies met inclusion criteria. Some factors, such as adaptive skills and the quality of the caring relationship, were consistently associated with carer mental well-being.