Circular economy (CE) enhances the integration of environmental issues into business practices. It appears as an opportunity to improve the environmental performance of stakeholders involved in its implementation. But CE requires technical and organizational changes in the practices of stakeholders to address some issues. The adoption of these changes involves a complex process with depends on multiple factors. Mobilizing Technology–Organization–Environment (TOE) framework, this paper aims to underline changes in CE implementation and their determining factors. Our analysis of data from 36 stakeholders of a CE project of Kamouraska (Quebec) underscores a weak influence of technological factors. Changes refer more to organizational resources, internal stakeholders, government regulation, geographical and social proximity, etc. In addition, the results show a causal relationship between different factors, which requires a systemic perspective on CE.