Introduction - an historical background, Peter Harper and Michael Morris; the clinical neurology of Huntington's disease, Oliver Quarrell and Peter Harper; psychiatric aspects of Huntington's disease, Michael Morris; natural history, Peter Harper; the neurobiology of Huntington's disease, Oliver Quarrell; social aspects, Audrey Tyler; management and therapy, Michael Morris and Audrey Tyler; epidemiology, Peter Harper; genetics, Peter Harper; linkage and molecular genetics, Duncan Shaw and Sandra Youngman; genetic counselling, Peter Harper and Audrey Tyler; predictive testing for Huntington's disease, Peter Harper and Michael Morris.