We sought to examine the mental and physical health and health-related quality of life of current and past carers compared to non-carers, using two instruments-the Short Form-12 (SF-12) and the EuroQol 5-dimension (EQ-5D). A total of 249 participants (34 current carers, 14 previous carers, 197 non-carers, 4 non-respondents) completed a baseline self-report survey at randomization into the larger study. Previous carers demonstrated moderate to severe anxiety or depressive symptoms measured with the EQ-5D (P < 0.001), reported on the SF-12 that they accomplished less because of emotional problems (P = 0.01) and more likely to have 'felt down' (P = 0.01) and used more health-care services than current or non-carers. Current carers tended towards a higher level of emotional problems and limitations to mobility than non-carers. This study indicates major differences in the well-being of these three cohorts. Health practitioners should pay particular attention to the mental health and health related quality of life of previous carers.