This paper reports findings from an evaluation of the local implementation of a procedural public health programme whose objective is to create healthy environments (HE) for vulnerable families in the province of Quebec (Canada) through the funding of local projects. Considering the potential issue of programme-context interaction, our research question was the following: Does the procedural nature of this HE programme result in variation between local cases in terms of the types of projects and collaborations it subsidizes? Given that the creation of healthy environments requires intersectoral health action to address social determinants of health, the data were analysed with respect to intersectorality and cooperation. Results of this qualitative multiple case study (n = 8), for the period 2004-2009, show that the majority of subsidized projects were in the health and social services sector and focused on parenting, parent-child attachment, nutrition and the social networks of families. Only a few initiatives reached beyond the health and social services sector to address social health determinants such as education, housing and transportation. Membership and mandates of the local groups responsible for programme implementation also showed little intersectorality. The limited variation between these eight cases can be attributed to the configuration of the local networks, as well as to specific issues in urban and rural areas. To explain the overall similarity of results across cases, we turned to the literature on policy instruments which suggests that particular characteristics of a programme may produce effects that are independent of its intended objective. In our study, several programme mechanisms, such as those framing the definition of "healthy environment" and budget management rules, could have encouraged the local development of initiatives that focus on individual skills related to parenting and attachment rather than the development of intersectoral health action to address social determinants of health.