Cannabidiol (CBD) is increasingly used as analgesic medication although the recent International Association for the Study of Pain Presidential Task Force on cannabis and cannabinoid analgesia found a lack of trials examining CBD for pain management. This trial examines CBD as add-on analgesic therapy in patients with hand osteoarthritis or psoriatic arthritis experiencing moderate pain intensity despite therapy. Using a randomized, double-blind, placebo-controlled design, patients received synthetic CBD 20 to 30 mg or placebo daily for 12 weeks. The primary outcome was pain intensity during the past 24 hours (0-100 mm); safety outcomes were percentage of patients experiencing adverse events and a characterization of serious adverse events. Explorative outcomes included change in Pittsburgh Sleep Quality Index, Hospital Anxiety and Depression Scale, Pain Catastrophizing Scale (PCS), and Health Assessment Questionnaire Disability Index. One hundred thirty-six patients were randomized, of which 129 were included in the primary analysis. Between-group difference in pain intensity at 12 weeks was 0.23 mm (95% confidence interval 29.41 to 9.90; P 5 0.96). Twenty-two percent patients receiving CBD and 21% receiving placebo experienced a reduction in pain intensity of more than 30 mm. We found neither clinically nor statistically significant effects of CBD for pain intensity in patients with hand osteoarthritis and psoriatic arthritis when compared with placebo. In addition, no statistically significant effects were found on sleep quality, depression, anxiety, or pain catastrophizing scores.