OBJECTIVES: Prior to use in an international study by NV Organon, the original 48-item menstrual Distress Questionnaire (MDQ), underwent linguistic validation in 26 languages. The original scale was developed in US English to assess the impact of common symptoms and feelings associated with the menstrual cycle. A rigorous methodology was required to ensure conceptual equivalence and cultural relevance across different languages. METHODS: The translation process was conducted by a specialist in each target country using the following standardized methodology: 1) two forward translations by professional translators who were native speakers of the target language and fluent in English; 2) comparison and reconciliation of the translations by the specialist in the target country and the translators; 3) back-translation by a native English speaker; 4) comparison of the original and back-translated versions; 5) review by a clinician; 6) comprehension test on 5 women; and 7) review for international comparability. RESULTS: The translation process revealed two major challenges. First, the formulation of some original items required the addition of a paraphrase or explanation in some languages. Second, the comprehension tests revealed that in countries where women are less used to completing questionnaires, the instructions asking the respondent to rate the same symptom/feeling for different times during a menstrual cycle were not always understood immediately. This required alternative wording in some translations. CONCLUSION: The 26 language versions of the MDQ were established according to a rigorous standardized translation methodology. The process aims to ensure conceptual equivalence across language versions to facilitate international comparison and pooling of data. The linguistic validation process illustrates the value of the integration of international feedback on concepts and wording during the translation of questionnaires.