The aim of this study was to determine the frequency and reasons for long-term opioid prescriptions (rxs) after surgery in the setting of guideline-directed prescribing and a high rate of excess opioid disposal. Although previous studies have demonstrated that 5% to 10% of opioid-naïve patients prescribed opioids after surgery will receive long-term (3-12 months after surgery) opioid rxs, little is known about the reasons why long-term opioids are prescribed. We studied 221 opioid-naïve surgical patients enrolled in a previously reported prospective clinical trial which used a patient-centric guideline for discharge opioid prescribing and achieved a high rate of excess opioid disposal. Patients were treated on a wide variety of services; 88% of individuals underwent cancer-related surgery. Long-term opioid rxs were identified using a Prescription Drug Monitoring Program search and reasons for rxs and opioid adverse events were ascertained by medical record review. We used a consensus definition for persistent opioid use: opioid rx 3 to 12 months after surgery and >60day supply. 15.3% (34/221) filled an opioid rx 3 to 12 months after surgery, with 5.4% and 12.2% filling an rx 3 to 6 and 6 to 12 months after surgery, respectively. The median opioid rx days supply per patient was 7, interquartile range 5 to 27, range 1 to 447 days. The reasons for long-term opioid rxs were: 51% new painful medical condition, 40% new surgery, 6% related to the index operation; only 1 patient on 1 occasion was given an opioid rx for a nonspecific reason. Five patients (2.3%) developed persistent opioid use, 2 due to pain from recurrent cancer, 2 for new medical conditions, and 1 for a chronic abscess. In a group of prospectively studied opioid-naïve surgical patients discharged with guideline-directed opioid rxs and who achieved high rates of excess opioid disposal, no patients became persistent opioid users solely as a result of the opioid rx given after their index surgery. Long-term opioid use did occur for other, well-defined, medical or surgical reasons.