To know the uptake of predictive testing of Huntington's disease, the characteristics of the applicants, as well as the consequences for them.Prospective observational study between January of 1994 and December of 1999 of the predictive testing applicants who entered in the protocol consisted of: informative interview, psychiatric interview, blood extraction for molecular study, as well as outcome and follow-up interviews.There were 87 applicants with a 50% risk. The mean age of the applicants was 28 years (SD = 7). Thirty one per cent already had children in the moment of predictive testing. The application rate according to the estimate population with 50% risk for the Comunidad Valenciana is 13,4%. The rate varies depending on the access to the information of the population in risk, being of 24,7% when they have direct access and of 8,3% when they do not have it (p < 0,01). Forty per cent did not come to the post-outcome visit, the positive or negative result for the mutation not influencing over it. Only 6,8% had some adverse event in the six years of follow-up all being slight.The application rate is determined by the access to the information of the population in risk. The fulfilment of the protocol designed for presymptomatic diagnosis of Huntington's disease keeps the adverse events presentation to a minimum.