Background: Whoonga is a smoked, heroin-based street drug in South Africa. Also known as nyaope, its use poses a significant public health and safety problem for South African communities. Studies have shown that smoked heroin-related treatment admissions have increased, but nothing is known about barriers and facilitators to treatment access.Methods: In 2015, semi-structured interviews were conducted with men undergoing residential substance use treatment in Durban, South Africa for smoked heroin use. In 2017, similar semi-structured interviews were conducted with men and women who smoke heroin and were recruited from the social networks of participants in residential substance use treatment. Participants were interviewed about their experience with the drug and substance use treatment. Interview data were coded using qualitative content analysis. Results: Interviews were conducted with 30 men in substance use treatment and 10 men and women from the social networks. Participants identified that the cost of substance use treatment, stigma related to substance use, and the addictive nature of the drug were barriers to treatment engagement. Although stigma among families led to alienation which made it difficult for the participants to leverage family resources to access treatment, direct family involvement in funding substance use treatment was an important facilitator to treatment access. Although we were expecting medication assisted treatment such as methadone to be a facilitator to treatment engagement, participants perceived methadone as another type of addiction and highlighted their own observations of how methadone was being abused in the community. Though neither barrier nor facilitator, improving physical health and repairing broken relationships were identified as motivators that influenced treatment engagement. Conclusion: There were a number of barriers to treatment access and very few facilitators, despite a lot of motivation to engage in treatment. Methadone could be a facilitator because it can overcome the addictive nature of the drug; therefore, work to change the perceptions of methadone in this population might enhance treatment access. Familial and social relationships were highlighted as barriers, facilitators, and motivators for substance use treatment engagement. Therefore, interventions targeting families might be a useful strategy to promote treatment engagement in those suffering from whoonga addiction. There are complex and overlapping social and biological forces at work and biobehavioral interventions that leverage motivators and facilitators to overcome barriers may have the most lasting impact on treatment engagement and treatment success.