It is widely accepted that cancer is an intersubjective experience that impacts upon the psychological well-being of people with cancer and informal carers, as well as on couple relationships. This qualitative study examined the nature and consequences of cancer on the relationship between informal carers and the person with cancer, from the perspective of Australian cancer carers. Sixty-two carers (42 women and 20 men), across a range of cancer types, stages and relationship dyads took part in semi-structured interviews.