The continuing rapid progress in medical virology is the result to a large extent of rapid advances in recombinant DNA techniques, in molecular and cell biology, in protein and nucleic acid chemistry, the use of monoclonal antibodies, progress in antiviral research and the application of modern technology to fundamental biological processes. These advances in knowledge of structural and biochemical components of viruses and mode of viral replication, understanding of cell pathology and immunopathogenesis have many health implications which include rapid, precise and specific diagnosis, epidemiology of viral infections, and the development of new types of vaccines, and emerging new infections. Strengthening of the links between the laboratory, fieldwork and the clinician is essential for implementing the strategy of the World Health Organisation's programme of health for all. Infectious diseases -and viral infections- are still responsible for most of the problems encountered daily in many parts of the world.The number of new journals introduced during the last two decades and the avalanche of information have made it virtually impossible for microbiologists, epidemiologists, pathologists, scientists and physicians to keep abreast of the scientific literature. We recognise the age of rapid dissemination of information retrieval by computerised systems, the ever published proceedings of meetings and symposia, abstract and rapid literature surveys, but it is secondary literature in the form of review series which has become useful as sources of information. However, their value depends intrinsically on authoritative and critical evaluation of the original data by experts in particular topics. The series Perspectives in Medical Virology was conceived after many discussions with teachers of postgraduate students, research workers, medical virologists, students and many colleagues.A number of distinguished practising virologists will be invited to assemble the important information available and to integrate research at the basic level with clinical practice in selected subjects for the new series. We hope that in this way the series will promote dissemination of information, useful discussion and exchange of ideas and stimulate further interest and research in medical virology.