Introduction Timely communication about life expectancy and end-of-life care is crucial for ensuring good patient quality-of-life at the end of life and a good quality of death. This article describes the protocol for a multisite randomised controlled trial of a nurse-led communication support programme to facilitate patients’ and caregivers’ efforts to communicate about these issues with their healthcare team.

Methods and analysis This NHMRC-sponsored trial is being conducted at medical oncology clinics located at/affiliated with major teaching hospitals in Sydney, Australia. Patients with advanced, incurable cancer and life expectancy of less than 12 months will participate together with their primary informal caregiver where possible. Guided by the self-determination theory of health-behaviour change, the communication support programme pairs a purpose-designed Question Prompt List (QPL—an evidence-based list of questions patients/caregivers can ask clinicians) with nurse-led exploration of QPL content, communication challenges, patient values and concerns and the value of early discussion of end-of-life issues. Oncologists are also cued to endorse patient and caregiver question asking and use of the QPL. Behavioural and self-report data will be collected from patients/caregivers approximately quarterly for up to 2.5 years or until patient death, after which patient medical records will be examined. Analyses will examine the impact of the intervention on patients’ and caregivers’ participation in medical consultations, their self-efficacy in medical encounters, quality-of-life, end-of-life care receipt and quality-of-death indicators.

Ethics and dissemination Approvals have been granted by the human ethics review committee of Royal Prince Alfred Hospital and governance officers at each participating site. Results will be reported in peer-reviewed publications and conference presentations.

Trial registration number Australian New Zealand Clinical Trials Registry ACTRN12610000724077.