A study using a high school and college sample (age 18–26) was conducted to validate the Slovak version of the Adult Decision-Making Competence. The results were similar to findings reported by Bruine de Bruin, Parker, and Fischhoff (2007) on the adult population in America. The internal consistency of component subscales and whole measure was confirmed as well as the factor structure. Gender differences in two of the six subscales were found. The results highlight the usefulness of A-DMC in assessing decision-making competence in Slovak language, but non-student samples are needed to enhance the generalisability of findings.