Abstract Background Despite improvements in medical care, patients with advanced cancer still experience substantial symptom distress. There is increasing interest in the use of medicinal cannabinoids, but there is little high quality evidence to guide clinicians. This study aims to define the role of cannabidiol (CBD) in the management of symptom burden in patients with advanced cancer undergoing standard palliative care. Methods and design This study is a multicentre, randomised, placebo controlled, two arm, parallel trial of escalating doses of oral CBD. It will compare efficacy and safety outcomes of a titrated dose of CBD (100 mg/mL formulation, dose range 50 mg to 600 mg per day)...