The decision to authorize a patient for continued enrollment in a state-sanctioned medical cannabis program is difficult in part due to the uncertainty in the accuracy of patient symptom reporting and health functioning including any possible effects on other medication use. We conducted a pragmatic convenience study comparing patient reporting of previous and current prescription opioid usage to the opioid prescription records in the Prescription Monitoring Program (PMP) among 131 chronic pain patients (mean age = 54; 54% male) seeking the first annual renewal of their New Mexico Medical Cannabis Program (NMMCP) license. Seventy-six percent of the patients reported using prescription opioids prior to enrollment in the NMMCP, however, the PMP records showed that only 49% of the patients were actually prescribed opioids in the six months prior to enrollment. Of the 64 patients with verifiable opioid prescriptions prior to NMMCP enrollment, 35 (55%) patients reported having eliminated the use of prescription opioids by the time of license renewal. PMP records showed that 26 patients (63% of patients claiming to have eliminated the use of opioid prescriptions and 41% of all patients with verifiable preenrollment opioid use) showed no prescription opioid activity at their first annual NMMCP renewal visit.