Resource allocation in mental health occurs at four levels. First, within the total allocation a society makes to health care, how much should go to mental health? In most societies, mental health services have been discriminated against. The quest for parity with medical and surgical services reflects the effort to undo this discrimination. In the Oregon priority-setting process, mental health conditions ranked high among community choices. Second, within the mental health sector, which conditions should receive priority? Some priority should be given to those with the most severe impairments, but no principles tell us just how much priority the sickest should receive. Third, within a particular area, such as schizophrenia, how much resource should be devoted to prevention, treatment of acute episodes, or rehabilitation of those with chronic conditions? Finally, in the care of individual patients, how much treatment is ‘enough’? Where and how is the line drawn between interventions regarded as ‘medically necessary’ versus interventions that are desirable but ‘optional’? In the absence of shared principles for making these allocational decisions, societies must establish fair decision-making processes, in which the rationales for policies and decisions are shared with the public, the rationales address meeting population needs in the context of available resources, and a robust appeals process allows patients, families, and clinicians to challenge decisions and policies. Because societies will develop their own distinctive approaches to resource allocation, progress requires looking at the allocation process in an international context.