Attitudes of 69 persons at risk for Huntington disease (HD) were obtained by means of semistructured interviews and questionnaires. About 79% of the individuals said that they would use a presymptomatic predictive test if it were available. All believed that the test should be made available even though there was no cure for HD. Nearly 2/3 of subjects would use the test for prenatal diagnosis, and of these 71% would terminate a pregnancy if the fetus was found to carry the HD gene. Most subjects believed that pretest counseling should be mandatory and many said that testing should be withheld from persons who were psychologically unstable or were threatening self-harm. The data suggest that about 2-6% of persons at risk for HD may have severe psychiatric or suicidal responses to a positive outcome of predictive testing. This underscores the need for adequate pretest counseling and the availability of professional and community resources to deal with the impact of predictive testing on individuals and their relatives.