Background Palliative care is expected to incorporate comprehensive support for family caregivers given that many caregivers suffer psychological morbidity. However, systematically implemented evidence‐based psychological support initiatives are lacking. Aim The objective of this study was to prepare caregivers for the role of supporting a patient with advanced cancer receiving home‐based palliative care by offering a one‐to‐one psycho‐educational intervention. We hypothesised that primary family caregivers who participated in the intervention would report decreased psychological distress (primary outcome), fewer unmet needs and increased levels of perceived preparedness, competence and positive emotions. Methods A three‐arm randomised controlled trial was conducted comparing two versions of the intervention (one face‐to‐face visit versus two visits) plus standard care to a control group (standard care) across four sites in Australia. Results A total of 298 participants were recruited; 148 were in the Control condition, 57 in Intervention 1 (one visit) and 93 in Intervention 2 (two visits). Relative to participants in the control group; the psychological well‐being of participants in the intervention condition was improved by a small amount but non‐significantly. No significant reduction in unmet needs or improvements in positive aspects of caregiving amongst the intervention group were identified. However, the intervention demonstrated significant improvements in participants' levels of preparedness and competence for Intervention 2. Conclusion/implications This research adds to accumulating body of evidence demonstrating that relatively short psycho‐educational interventions can enable family caregivers to feel more prepared and competent in the role of supporting a dying relative. Further investigation is required to determine the longer term outcomes of such interventions. Copyright © 2013 John Wiley & Sons, Ltd.