Background Osteoarthritis (OA) can result in significant pain, requiring pain management with opioids. Medical cannabis (MC) has the potential to be an alternative to opioids for chronic pain conditions. This study investigates whether MC used in the management of OA-related chronic pain can reduce opioid utilization. Methods Forty patients with chronic OA pain were certified for MC. Average morphine milligram equivalents (MME) per day of opioid prescriptions filled within the six months prior to MC certification was compared to that of the six months after. Visual analog scale (VAS) for pain and Global Health scores were measured at baseline, three, and six months post MC certification. Results Average MME/day decreased from 18.2 to 9.8 (n=40, p<0.05). The percentage of patients who dropped to 0 MME/day was 37.5%. VAS scores decreased significantly at three and six months, and Global Physical Health score increased significantly by three months. Conclusions MC reduces opioid prescription for patients with chronic OA pain and improves pain and quality of life.