Purpose <p>Collaboration between domestic and family violence (DFV) and substance use sectors can enhance client outcomes, however, it also presents challenges. This study identified areas of inquiry, which created collaborative flows and bottlenecks between domestic violence and substance use professionals.</p> Methods <p>Adopting a system’s approach to action research, an Australian Policy Stakeholder Group was formed. Over a two-year period, senior policy workers, practitioners, and managers convened to identify ways to reduce sectoral silos. The authors analyzed themes contributing to collaborative flows and bottlenecks. Metaphor analysis was also used to reveal the implicit assumptions participants held about these themes. </p> Results <p>Three themes facilitated collaborative flow: increasing consensus that the relationship between substance use and DFV is complex; integrating substance use content into supportive interventions for victim-survivors; and the concept of substance use coercion. These facilitated open negotiations of contested worldviews among participants. Three themes led to collaborative bottlenecks: short-term funding cycles; the (de) gendering of DFV; and disputed notions of accountability for people who use violence. Metaphor analysis revealed that collaborative bottlenecks were conceived as contentious terrain, causing apprehension amongst participants.</p> Conclusions <p>Collaborative flows and bottlenecks between DFV and substance use sectors evolve over time. Professionals navigating them must be cognizant of context that influences collaborative dynamics, which can enhance the support provided to families affected by DFV and substance use.</p>