Reintegration after prison for prisoners with interlinked welfare needs has been one of the most challenging issues for decades in the criminal justice system. The WHO and the UN highlight the demand for well-functioning collaboration between professionals and welfare agencies handling these challenges. However, interprofessional collaboration has been an underdeveloped field of research and theory, especially concerning prisoners with substance abuse issues. The present study undertakes a scoping review of research on interprofessional collaboration in reintegration after prison for prisoners with substance abuse issues, particularly identifying factors that influence collaboration. Nineteen included studies from the USA, the U.K., Australia, and Norway show that relational and structural factors influence collaboration and that innovative projects are perceived as improving collaboration. A tentative conceptual model of factors that influence collaboration is presented and may serve as a basis for reflection and further development of a theoretical framework within the field of research. Keywords: interprofessional collaboration, prisoners, prison, reintegration, scoping review