This chapter presents an overview of general ethical principles of justice to health care, an application of these principles to resource allocation in relation with mental health care, an introduction of the concepts of necessary care and solidarity, as well as need and outcome based approaches. While the needs of mental health patients are widely recognised, needs are generally seen as subjective and difficult to distinguish from preferences or wishes of individuals. An alternative approach is the concept of ‘burden of disease’ which gives a measurable indication of the problems of individuals in need of treatment. Burden of disease should be combined with evidence on the effectiveness of treatments, as produced in randomised controlled trials (RCTs). The use of evidence on effectiveness and cost-effectiveness studies has become increasingly prominent in so-called evidence-based policies on resource allocation in health care, including mental health care. However, the use of evidence-based medicine in the allocation of scarce resources may lead to a one-sidedness and to unfair priorities within mental health care. The author concludes that out-come oriented approaches should be mixed with a measurement of the burden of disease and should also take into account our solidarity with the most vulnerable groups.