Background: We evaluated the effectiveness of a simple, low-cost educational brochure in improving disposal rates of unused opioids after outpatient upper extremity surgery. Methods: This cross-sectional study enrolled eligible adult patients from a peripheral nerve clinic between November 2017 and September 2018. Patients either received or did not receive the educational brochure, which outlined a simple method to dispose of unused opioids and completed a survey at 2 weeks after surgery. We compared the proportion of patients who disposed of unused opioids after surgery between the group that had received the brochure and the group that had not. Categorical data were analyzed with χ2 test, proportions data with binomial tests, and numerical data with Mann-Whitney U test, all with a significance level of P <.05. Results: There were 339 survey respondents. Nineteen patients who did not meet inclusion criteria were excluded. Of the 320 remaining patients, 139 received the brochure and 181 did not. An additional 55 patients were excluded due to preoperative opioid use. Overall, 35.3% of recipients and 38.3% of those who did not receive the brochure used all of their prescribed opioid medication (P =.625; confidence interval = −14.6%-8.8%). Among patients with unused opioid medication, a significantly higher proportion of brochure recipients disposed of the medicine compared with those who did not receive the brochure (46.7% vs 19.6%, P <.001). Conclusions: Distribution of an educational brochure significantly improved disposal of unused opioids after surgery. This easily implemented intervention can improve disposal of unused opioids and ultimately decrease excess opioids available for diverted use in the community.