The "Protocolo de Avaliação Miofuncional Orofacial MBGR" was developed in the Brazilian Portuguese language to assess and diagnose orofacial myofunctional disorders in the Brazilian Portuguese-speaking population. Considering its extensive use in clinical practice and in scientific studies, the indispensability of participation of professional translators in every translation procedure, the existence of studies in the literature that recommend specific guidelines for the process of translation and cross-cultural adaptation of health-related instruments, and the prevalence of the North American English language in the dissemination of technical and scientific knowledge, the objective of this study was to perform the translation and cross-cultural adaptation of the updated "Protocolo MBGR" from the Brazilian Portuguese language into the North American English language according to the guidelines for translation and cross-cultural adaptation of health-related instruments proposed by Beaton et al. (2000), aiming at the dissemination of both the updated "Protocolo MBGR" and the technical and scientific knowledge in Speech-Language Pathology area, specifically in the Orofacial Myology area, produced in Brazil. The guidelines proposed by Beaton et al. (2000) recommend six steps: (1) translations, (2) synthesis of translations, (3) back translations, (4) expert committee, (5) pretests, and (6) submission of the documentation to a coordinating committee.In the first step, two translations into English were done by two different native Englishspeaking translators. In the second step, these two translations were compiled in order to reach a synthesis version. In the third step, the synthesis version of the translations was backtranslated into Portuguese by two native Portuguese-speaking translators. In the fourth step, translators, back translators, and other specialists, including Speech-Language Pathologists, established the pre-final English version of the "Protocolo MBGR" to be tested; each participant scored from 1 to 4 (1 = not relevant, 2 = somewhat relevant, 3 = quite relevant, 4 = highly relevant) each item of the pre-final English version of the "Protocolo MBGR" according to the Content Validity Index (CVI), in order to measure the percentage of experts who were in agreement with the translation of the items. In the fifth step, which was held at the University of South Florida, tests were performed in order to establish the final English version of the "Protocolo MBGR". In the first phase of the pretesting, the pre-final English version of the "Protocolo MBGR" was analyzed and evaluated by 15 North American Speech-Language Pathologists in order to verify the quality and clarity of its translation and cross-cultural adaptation; in the second phase of the pretesting, the pre-final English version of the "Protocolo MBGR" readjusted from the analyzes and evaluations of the first phase of the pretesting was re-analyzed and re-evaluated by five other North American Speech-Language Pathologists in order to verify the qua...