Background The Domus study, a randomized controlled trial (RCT), evaluated the effect of home-based specialized palliative care (SPC) reinforced with a psychological intervention for the patient-caregiver dyad on increasing advanced cancer patients' time spent at home, as opposed to hospitalized, and the number of home deaths. As palliative care extends to include support for patients' families and may thus assist caregivers and decrease demands on them, in this study we evaluated a secondary outcome, caregiver burden. Material and Methods Patients with incurable cancer and their caregivers were randomized (1:1) to care as usual or home-based SPC. Caregiver burden was assessed using the Zarit Burden Interview (ZBI) at baseline and 2, 4, 8 weeks and 6 months after randomization. Intervention effects were assessed in mixed effects models. Results A total of 258 caregivers were enrolled. Eleven per cent of informal caregivers experienced severe caregiver burden at baseline. Caregiver burden increased significantly over time in both groups ( p  = 0.0003), but no significant effect of the intervention was seen on overall caregiver burden ( p  = 0.5046) or burden subscales measuring role and personal strain. Conclusion In line with the majority of previous RCTs, the Domus intervention was not able to significantly reduce caregiver burden. Future interventions should consider targeting only caregivers reporting the greatest caregiver burden.