Objective: This study translated the Portuguese version of the Multiple Sclerosis Quality of Life-54 (MSQoL-54) questionnaire. Methods: The original version of 18 items from the MSQoL-54 was translated into Brazilian Portuguese using international guidelines. Two independent translations were completed by Brazilians fluent in English and the results were evaluated and harmonized, concluding version: 1. This version was back-translated by an American living in Brazil and then another analysis was conducted, resulting in version 2. Concluding the translation and harmonization phase, the final version was pre-tested with ten participants from the Reference Centre for Multiple Sclerosis at the Porto Alegre Clinical Hospital in Rio Grande do Sul (RS)-Brazil. Results: The questionnaire was well accepted by the patient’s sample that tested the 18 specific items. They presented no conceptual problems. Conclusion: Patients with multiple sclerosis (MS) felt the questionnaire was easy to understand. We thus attained terms of conceptual equivalence between the original questionnaire and the translation
