Aphasia nearly affects half of all poststroke patients. Furthermore, aphasia affects all language functions, well-being, and quality of life of patients. Therefore, rehabilitation of patients with aphasia requires an accurate assessment of language function and psychological aspects. However, assessment scales for language function and psychological aspects of patients with aphasia are said to be inaccurate. In Japan, this sign is more prominent than in English-speaking countries. Therefore, we are putting together a scoping review of research articles published in English and Japanese to date, with the aim of summarizing the accuracy of rating scales for language function and psychological aspects of people with aphasia. The scoping review was intended to be a comprehensive examination of the accuracy of rating scales for people with aphasia. We will search the article databases PubMed, MEDLINE, Embase, PsycINFO, Web of Science, and the Medical Journal Web (Japan). The observational studies that describe the reliability and validity of the rating scales in adult aphasic after stroke will be searched for. There will be no publication date for the articles that will be searched. We believe that this scoping review aims to assess the accuracy of rating scales used to measure different aspects of aphasia, with a focus on research conducted in English-speaking countries and Japan. By conducting this review, we believe to identify any problems with rating scales used in English and Japanese research and improve their accuracy.