Introduction: The concept of mind wandering refers to periods during which attention and content of thoughts depart from the original idea or activity being performed. The phenomenon occurs commonly in the general population and the Mind Wandering Excessively Scale (MEWS) evaluates its frequency, intensity and related negative outcomes. Objective: To describe the cross-cultural adaptation of the MEWS. Methods: Cross-cultural adaptation of the original scale followed five consecutive steps: translation, backtranslation, appreciation of semantic equivalence and administration to a convenience sample to 20 adults with attention deficit hyperactivity disorder (ADHD) and 20 normal controls. Results: Results indicated a satisfactory equivalence between the original and translated versions. A synthesis version for Brazilian Portuguese is presented. Conclusions: MEWS provides information on thought activity, which is particularly important in ADHD cases. The Brazilian Portuguese version would be welcome to address specific treatment responses and obtain new outcome measures
