There is evidence indicating instances of gambling-related harms among people accessing substance misuse services. What is unknown are the challenges presented to these professionals when identifying and addressing these hidden harms. The aim of this research is to investigate the barriers and facilitators for drug and alcohol workers in addressing gambling harms within substance misuse settings. Thirty-four semi-structured, online interviews were conducted. Participants were recruited across the North East of England and included staff from specialist charity services, local authorities and primary care treatment services. Thematic analysis of transcripts identified five themes, which were inter-connected and reinforced the practitioners’ difficulties in identifying the hidden harm of gambling. The five themes comprised of no training or awareness on gambling, stigma as a barrier within their services, gambling not being prioritized by management, drug and alcohol services not being commissioned to treat gambling harms, and the perception that not asking the question helps no one. Although conducted in the North East of England, the findings highlight broader systemic challenges for substance misuse services in identifying and responding to gambling-related harms. We concluded that client welfare could be improved through preventative approaches, including signposting or referral routes to a gambling-specific treatment services.