The aim of this study was to explore factors that facilitate or impede collaboration in a Canadian context. Qualitative in-depth interviews were conducted with a purposive sample of 24 managers and direct service staff from substance use treatment and the child welfare fields in different regions of a Canadian province. Findings underscore the importance of examining cross-system collaboration specific to regional policy contexts, such as British Columbia's harm reduction approach to substance use and addiction. At the same time, many of the barriers and driving forces for collaboration found in this study echo the experiences of other countries.