The purpose of this study was to develop an empirically derived multi-item scale of care tasks performed by young people in the context of family illness/disability: the Youth Activities of Caregiving Scale (YACS). A total of 135 youngsters aged 10–24 years with an ill/disabled family member completed questionnaires. Factor analyses performed on the YACS yielded four factors, instrumental care, social/emotional care, personal/intimate care and domestic/household care, accounting for 57.78% of the variance. The internal reliabilities of all factors ranged from 0.74 to 0.92. Higher scores on the YACS related to higher youth age and several caregiving context variables (i.e. household type [single or dual-parent household], relationship with care-recipient and perceived choice in caregiving). Higher scores on the YACS also related to care-recipient illness/disability variables (onset, functional impairment, prognosis, predictability and illness/disability type). Strong positive correlations between the YACS and a conceptually related measure of young caregiving experiences provided good convergent validity data. Criterion validity was established with evidence that the YACS predicted youth adjustment in the domains of health and prosocial behaviour.