Objective: Patients with a combination of chronic pain and opioid use disorder have unique needs and may present a challenge for clinicians and health care systems. The objective of the present study was to use qualitative methods to explore factors influencing the uptake of best practices for co-occurring chronic pain and opioid use disorder in order to inform a quantitative survey assessing primary care provider capacity to appropriately treat this dual diagnosis. Methods: Guided by the Consolidated Framework for Implementation Research (CFIR), semi-structured qualitative interviews were conducted with 11 primary care providers (PCPs) to inform the development of a questionnaire. Interviews were audio-recorded and transcribed verbatim. Fifteen comments from an open-ended question on the questionnaire were added to the analyses as they described factors that were not elucidated in the interviews. Barriers and facilitators were identified and categorized using the CFIR codebook. Results: The most frequently described barriers were cost and inadequate access to appropriate treatments, external policies, and available resources (e.g., risk assessment tools). The most frequently described facilitators were the presence of a network or team, patient-specific needs, and the learning climate. Knowledge and beliefs were frequently described as both barriers and facilitators. Conclusions: While substantial funding has been allocated to initiatives aimed at increasing PCP capacity to treat this population, numerous barriers to adopting appropriate practices still exist. Future research should focus on developing and testing implementation strategies that leverage the facilitators and overcome the barriers illustrated here to improve the uptake of evidence-based recommendations for the treatment of co-occurring chronic pain and opioid use disorder.