BACKGROUND: Overdose from opioids is a serious public health and clinical concern. Veterans are at increased risk for opioid overdose compared with the civilian population, suggesting the need for enhanced efforts to address overdose prevention in Department of Veterans Affairs (VA) health care settings, such as primary care clinics. METHODS: Prescribing providers (N = 45) completed surveys on baseline knowledge and concerns about the VA Overdose Education and Naloxone Distribution (OEND) initiative prior to attending an OEND educational training. RESULTS: Survey items were grouped into 4 OEND-related categories, reflecting (1) lack of knowledge/familiarity/comfort; (2) concerns about iatrogenic effects; (3) concerns about impressions of unsafe opioid prescribing; and (4) concerns about risks of naloxone prescribing. Although certain OEND-related categories were associated with each other, concerns related to iatrogenic effects of OEND (e.g., patients will use more opioids and/or be less likely to see treatment) and lack of knowledge/familiarity/comfort with OEND were endorsed more than concerns related to giving impressions of unsafe opioid prescribing. The majority of providers endorsed the belief that those prescribing opioids to patients should be responsible for providing overdose education to those patients. System-wide naloxone prescription rates and sources increased over 320% following initiation of OEND expansion efforts, although these increases cannot be viewed as a direct result of the in-service trainings. CONCLUSIONS: Findings demonstrate that some providers believe they lack knowledge of opioid overdose prevention techniques and hold concerns about OEND implementation. More training of medical providers outside substance use treatment settings is needed, with particular attention to concerns about harmful consequences resulting from the receipt of naloxone.