This article investigates the relationships of child- and family-related variables with family function in families with children who have Duchenne muscular dystrophy. Child-related variables included level of disability (indicator: Barthel Index) and age at diagnosis. Family-related variables included caregiver health status (indicator: Duke Health Profile), family income and employment, family support (indicator: Family APGAR), family hardiness (indicator: Family Hardiness Index), and family functioning (indicator: Family Assessment Device). Family function displayed a significant correlation with age at diagnosis, but not with disability level. It was also significantly correlated with family hardiness, caregiver health status, and levels of family support, but not with income or employment variables. These findings highlight the need to assist families to cope with the presence of serious illness in their children.