|The objective of this work is to present the validation of an instrument to measure the psychological adaptation in parents to a disease or genetic risk in their children: Psychological Adaptation Scale to Genetic Counseling. A methodological study was carried out, with a sample of 203 cases. Construct validity was studied by a parallel analysis and an exploratory factor analysis. The significance of the Bartlett sphericity test (χ2 (105) = 1928.4; p < .001) was significant and the Kaiser-Meyer-Olkin (KMO) sample adequacy index indicated an adequacy of .87. A single factor was obtained that explained 45% of the variance. Reliability was studied using the Cronbach’s alpha coefficient, finding a high value of internal consistency α = .915. The present study offers the first valid and reliable instrument in Spanish to measure, in parents, their psychological adaptation to a disease or genetic risk in their children.