Objective: The objective of this study was to estimate the association between health care practitioner counseling on medication disposal and disposal of unused opioid medications. Design: A 41-item survey instrument was created and administered to a nationally representative panel of adult opioid users with chronic pain using a cross-sectional, internet survey design via Qualtrics®. Participants: Four hundred adult opioid users with chronic pain were randomly selected from the Qualtrics® panel-base to participate. Setting: United States. Outcome measures: The dependent variable, disposal of unused opioid medications, was assessed with a single item asking participants how often they had disposed of unused opioid medications in the past year. Multiple logistic regression was used to assess the association between opioid disposal and the receipt of health care practitioner counseling on medication disposal. Results: A total of 400 surveys were completed. Participants were mostly white (70.8%) and under the age of 40 (54.1%). Less than one-half of all participants (44.5%) had disposed of opioid medications in the past year, while 60.75% had received health care practitioner counseling on disposal. Of those counseled, only 21.4% were counseled by a pharmacist. Flushing medication down the toilet (33%) was the most common method of opioid disposal. After adjustment for covariates, those who received health care practitioner counseling were more likely to have disposed of opioid medications in the past year (adjusted odds ratio 1.66, 95% CI 1.03-2.69). Conclusions: Participants who received counseling on opioid disposal were more likely to have disposed of unused opioid medications. Pharmacists are uniquely positioned to counsel patients on opioid disposal and thus must be active in preventing harm and diversion due to improperly stored opioid medications. This study demonstrates the need for enhanced provider education and policy to ensure that patients are adequately counseled on proper opioid disposal.