People need information to choose a physician, a hospital, or to take part in a decision about their treatment. There is little knowledge about what information people want or need to make these choices. Yet there is a growing view in Europe that more and better information should be available to the public about service quality and outcomes. This paper considers the collection, analysis and presentation of health service quality and outcome information for use by patients to make decisions about a provider and about a treatment. It considers why this subject is now a public health and policy issue in Europe, reviews experience in the USA and Europe to gathering and giving this information, and describes the technical, socio-political and ethical issues involved. It concludes that whilst advances have been made in overcoming the technical and cost problems, we do not yet know enough about the information which people want or can use to justify large scale publicity schemes. It proposes that global quality information about a hospital or other service as a whole is less useful. Progress is best made on a specialty or treatment basis, especially where there are large unexplained variations, and by involving patient groups in defining the information which patients with specific health conditions most value. It notes how these developments are leading to new types of collaboration between health workers and patients to increase both patient's and professional's knowledge of the course of an illness or treatment.