This article draws on both published and unpublished private family writing to examine how European settler colonial families in southeastern Australia and New Zealand negotiated worlds of sickness and health between 1850 and 1910. It argues that personal writing is a neglected yet rich repository for shedding light on colonial cultures of health across families and households in colonial Australia and New Zealand. In examining challenges to well-being and gendered lay health care practices inside domestic spaces, we glimpse more than worlds of health and treatment. Through their management of health and illness in private domestic spaces, the sense of well-being colonial families created for their members tells us something both about their emotional lives and cultures of colonialism.