The purpose of the needs assessment was to identify gaps, overlaps, strengths of the addictions prevention and treatment services accessed by the Region’s First Nations population. [...] The aim of the regional needs assessment process coincides with First Nations concerns and is intended to ensure that the region’s First Nations communities have access to an effective, sustainable and culturally-appropriate continuum of addictions prevention and treatment services. [...] It is their wisdom and knowledge that is shared in this report and will inform decision- makers within First Nations communities, the First Nation and Inuit Health Branch and First Nation and Inuit Health Ontario Region, First Nation leaders, the government of Ontario and service providers regarding improving addiction prevention and treatment services for First Nations people in Ontario. [...] Nature of Study As part of the Addictions Evidence-Based process occurring within the First Nations and Inuit Health Branch (FNIHB) of Health Canada, Ontario Region First Nations and Inuit Health (FNIH) together with the Chiefs of Ontario (COO) undertook a needs assessment of the Region’s addictions services. [...] The purpose of the needs assessment is to identify gaps, overlaps, strengths of the addictions prevention and treatment services accessed by the Region’s First Nations population.