This study examines the barriers and facilitators of retention among patients receiving buprenorphine/naloxone at eight community-based opioid treatment programs across the United States. Participants (n = 105) were recruited up to three and a half years after having participated in a randomized clinical trial comparing the effect of buprenorphine/naloxone and methadone on liver function. Semi-structured interviews were conducted with 67 patients provided with buprenorphine/naloxone who had terminated early and 38 patients who had completed at least 24 weeks of the trial. Qualitative data were analyzed using the constant comparison method. Barriers to buprenorphine/naloxone retention that emerged included factors associated with: (1) the design of the clinical trial; (2) negative medication or treatment experience; and (3) personal circumstances. The facilitators comprised: (1) positive experience with the medication; (2) personal determination and commitment to complete; and (3) staff encouragement and support. The themes drawn from interviews highlight the importance of considering patients' prior experience with buprenorphine/naloxone and methadone, medication preference, personal circumstances, and motivation to abstain from illicit use or misuse of opioids, as these may influence retention. Ongoing education of patients and staff regarding buprenorphine/naloxone, especially in comparison to methadone, and support from staff and peers are essential.