Many public health and social issues faced by society today are multifaceted and require joint and collaborative efforts through health promotion partnerships. Community-based participatory research (CBPR) is one strategy that consists of engaging community stakeholders from various sectors to pool their expertise and resources in addressing health and social issues holistically. The literature indicates that the effectiveness of partnerships, such as those established within CBPR initiatives, is influenced by collaborative mechanisms that promote the creation of synergy among partners. There is, however, a lack of knowledge with regards to synergy and its key determinants in the context of health promotion partnerships. This qualitative thesis study is conducted as part of The EnRiCH Project, a CBPR initiative conducted in four communities across Canada, which aims at enhancing resilience and preparedness for disasters among high-risk populations. It explores the creation of synergy through the study of dynamics of collaboration shaping the EnRiCH-Québec City partnership and influencing its ability to leverage community resources for emergency preparedness. Emergent themes highlight that optimal collaboration in the EnRiCH-Québec City partnership is about having the “right people, in the right place, at the right time”. These findings provide evidence to inform community stakeholders, researchers and decision-makers on the dynamics of synergy creation and its implications for partnership growth and effectiveness.