Wellesley Institute and the Centre for Addictions and Mental Health (CAMH) have joined forces to start an ambitious project which will make the case for diversity in mental health services. The Mental Health Commission of Canada (MHCC) have put the development of equitable services for immigrant, refugee, racialized and ethno-cultural groups as one of the most important focusses of a transformed service. The population of every province and territory is coming increasingly diverse. High rates of mental health problems have been reported in some ethnic groups however, there is often lower use of mental health services because of a variety of barriers to care. Equitable care will require efforts to decrease rates of illness as well an improvements in access to services and the outcomes of treatment. Across the world and in various parts of Canada, new service models have been developed to meet the needs to a multi-cultural population but health planners do not know which work, which do not and how to develop a service response that meets the needs of all their citizens. The case for diversity will include literature reviews, reviews of promising practices and economic analyses to help clinicians, policy makers and planners.