In this investigation of 133 grandparents with primary responsibility for their grandchildren, we examined the potential moderating role of social support in the association between caregiver stressors and grandparents' general well-being. Enacted formal support buffered the association between grandchild health problems and both grandparent caregiving stress and life satisfaction. Enacted formal support also buffered the association between parenting daily hassles and life satisfaction. Compensatory or main effects of perceived informal and formal social support were found for both grandparent caregiving stress and life satisfaction. Findings highlight the importance of professional assistance and community services in minimizing the negative impact of child-related challenges on grandparents' well-being.