Purpose: As recovery time after oncological surgery can be long, family caregivers often play an important role in the delivery of care after patients' discharge. To prepare carers for this role, we developed a family involvement program (FIP) to enhance their active involvement in post-surgical oncology care during hospitalization. The purpose of this qualitative study was to explore family caregivers experience of participating in a FIP. Methods: We conducted semi-structured interviews with 12 family caregivers who participated in the family involvement program. The program is comprised of two main components (1) training and coaching of physicians and nurses; (2) active involvement of family caregivers in fundamental care activities. This active involvement included six activities. Data were analyzed using interpretative phenomenological analysis. Results: Family caregivers positively valued the program. Active participation in post-surgical care was experienced as an acceptable burden. The program gave participants the ability to simply be present ('being there') which was considered as essential and improved their understanding of care, although family caregivers sometimes experienced emotional moments. Active involvement strengthened existent relationship between the family caregiver and the patient. Participants thought clinical supervision. by nurses is important. Conclusions: Physical proximity appeared as an essential part of the family involvement program. It helped carers to feel they made a meaningful contribution to their loved ones' wellbeing. Asking families to participate in fundamental care activities in post-surgical oncology care was acceptable, and not over-demanding for caregivers.