This research focused on the planning and development phase of the Moncton site of At Home / Chez Soi, a multisite research demonstration project funded by the Mental Health Commission of Canada, developed to test an innovative approach to working with homeless people living with severe and persistent mental illness in 5 Canadian cities. Using qualitative methods, 11 local key informants participated in semistructured interviews focusing on: (a) early planning processes; (b) principles and values guiding the planning process; (c) planning actions; and (d) stakeholder relationships. We found that contextual elements, especially those related to the small size and bilingual nature of the city and the lack of mental health services in the area, had a significant impact on the planning and development of the project in Moncton. The implications of findings for future planning of complex community interventions are noted.