Rising health care costs now confront policy makers and planners with serious dilemmas of choice. This publication seeks to help formulate principles by which choices can be made. It begins with the premise that health demands will outstrip available resources, but argues that this should not mean that every allocation can be ethically defended. It proposes that allocations should be made in the light of four principles: beneficience, non-maleficence, justice and respect for autonomy. This approach provides a way of thinking about the issues systematically and explicitly.