Family caregivers of an older person who was recently hospitalized often feel unprepared for their new or expanded tasks. Quality and continuity of care for older people is expected to improve when nurses collaborate with family caregivers as partners in care. The aim of this study was to explore the unique contribution of collaboration between family these caregivers of older patients and hospital nurses as a possible predictor for preparedness of caregiving after hospital discharge. With a cross sectional design, a postal survey was sent to 777 family caregivers of home-dwelling hospitalized patients (≥70 years). Regression analyses were used to test the association between collaboration and preparedness for caregiving. In total, 506 (68%) family caregivers responded of whom 281 (38%) were eligible. Their mean (SD) age was 65 (13) and 71% were female. Family caregivers’ level of collaboration with nurses was significantly associated with their preparedness for caregiving.