Using two waves of survey data on family carers caring for older adults with multiple chronic conditions in Ontario and Alberta, this article provides a sex and gender analysis of 194 carers' health outcomes. Gender and sex differences were examined on the following health outcomes: general self-efficacy; physical and mental health composite scores; overall quality of life; and the Zarit Burden Inventory – as well as experiences with work interference for carer-employees. Multivariate ordinary least squares linear regressions were used to estimate the effects of sex and gender, controlling for the carer's socio-demographic and geographic characteristics, as well as for the characteristics of the care recipients. Sex and gender were found to have differentiated effects on each health outcome examined, providing evidence for specifically targeting health interventions by sex and gender. First, sex matters, as illustrated by the fact that female carers were found to be experiencing more negative health impacts than male carers (shown in the physical composite score and the quality of life score). This suggests that health-related interventions need to be targeted at female carers. Further, male carers are more likely to experience less carer burden, and more work interference, than female carers. Second, gender matters, as illustrated by the fact that masculine and androgynous genders showed significantly positive associations with general self-efficacy. This suggests that carers with feminine and undifferentiated gender roles experience more challenges with general-self-efficacy and could benefit from training and educational interventions to enhance their confidence in the caring role.