Recovery theory is well established in research, policy, and treatment practice in the UK, US and Australia and has begun to emerge recently in the Belgian research context, as well as in policy since 2015. However, recovery (and particularly social) capital among substance users with a migration background remains understudied in national as well as international literature. The aim of this research project is to study 1) the nature of recovery (and particularly social) capital in substance users with a migration background, 2) the impact of hypothesized factors (socio-economic disadvantage, social capital [social network, social and ethnic identity] and double stigma [perceived discrimination and stigma]) on addiction recovery in this population, and to compare 3) the identified needs and successes in addiction recovery with the components of and variations among theories of culturally competent substance abuse treatment (SAT). To this end, we will recruit 120 study participants in early (less than 1 year), sustained (over a year and less than 5 years) and stable recovery (over 5 years). The study will use mixed methods to assess in-depth the impact of the hypothesized variables, and remain open to emerging contextual factors impacting addiction recovery and recovery capital, with a particular focus on social capital and differences between persons with an intra- and non-European migration background, as the former population is particularly underrepresented in Flemish SAT.