There are concerns that cannabis use disorder (CUD) may develop in chronic pain patients prescribed medical cannabis (MC). The criteria for CUD according to the Statistical Manual for Mental Disorders Version 5 (DSM-5) were not developed for identification of patients using cannabis for therapeutic reasons. In addition, some items of CUD might be attributed to the desire of the patient to relieve the pain. Therefore, alternative strategies are needed to identify the true prevalence of CUD in persons with chronic pain being treated with MC.The prevalence of CUD in chronic pain patients according to the DSM-5 criteria was assessed using an anonymous questionnaire in 187 consecutive patients attending three German pain centres in 2021. Questionnaires were rated as follows: 1) all criteria included; 2) removal of items addressing tolerance and withdrawal; 3) removal of positive items if associated with the desire to relieve pain. Abuse was assessed by self-report (use of illegal drugs; diversion and illegal acquisition of MC) and urine tests for illegal drugs Physicians recorded any observation of abuse.CUD according to the DSM-5 criteria was present in 29.9%; in 13.9% when items of tolerance and withdrawal were removed; in 2.1% when positive behaviour items were removed. In 10.7% at least one signal of abuse was noted. Urine tests were positive for non-prescribed drugs (amphetamines, tranquilizer) in 4.8% of subjects. Physicians identified abuse in one patient. In this study, the DSM-5 criteria overestimated and physicians underestimated the prevalence of CUD in patients prescribed MC for chronic pain.