--- - |2 Abstract After 25 years of intersectoral practice to increase health promotion resources, there is little scientific literature linking analysis of processes to observation of effects. Applying Actor–Network Theory, this article examines how the effects of intersectoral action are produced and can be attributed to its processes. A prospective multiple case study (2013–2016) was conducted on Neighbourhood Committees (NCs) in Montreal (Canada). Three NCs were studied using four kinds of data: direct observation notes of meetings and events, documents, logbooks and interviews. Systemic modelling of local intersectoral action was used for data collection and analysis. The results show that the transformations in living environments were produced by sequences of a limited number of ‘transitory outcomes’ that mark the progression of intersectoral action up to its effects. The list of transitory outcomes identified make up three functions in the production of change: (i) network setup and governance; (ii) self‐representing and influencing others; (iii) aligning necessary actors and resources. The production of effects follows a systemic model wherein unique configurations of transitory outcomes, adapted to the different contexts where interactions are occurring, represent the change processes that lead to the effects. - 'Sociology of Health &Illness, EarlyView. '