The issue of publishing duplicate or highly similar content in multiple languages in scientific journals is complex, and its acceptability is subject to certain ethical controversies. Authors often publish the same content in different languages to maximize the dissemination of their work or increase the quantity of their publications. This duplicate form of publication has drawn significant attention from journal editors because of its ethical implications. However, international and domestic publishing standards are not fully unified on this matter, and the different perspectives of journal editors and authors further complicate the issue. In practical publishing activities, ethical dilemmas often involve complex trade-offs, and understanding different ethical viewpoints can help editors address moral challenges more comprehensively. Therefore, it is necessary to discuss the ethical issues of publishing duplicate content in multiple languages. First, this article reviews relevant provisions in copyright laws and academic publishing standards in China, as well as the attitudes and recommendations of international publishing ethics guidelines. It finds that domestic laws lack clear regulations on this issue, whereas international guidelines neither support nor oppose it, whose perspective maintains a neutral stance on the ethical requirements for such situations. The article analyses ethical issues from the perspectives of three stakeholders: authors, journals, and the public. Authors hope to increase the number of their publications and gain more benefits through this approach, but publishing the same content in different languages is usually recognized as independent research achievements, which is unfair in academic evaluation. Owing to the above, several major international publishers, such as Elsevier, Springer Nature, Wiley, and Taylor & Francis, have established their own rules and policies on the basis of their interests and in alignment with the guidelines. Next, by analysing three specific cases of duplicate publications in different languages, two from domestic Chinese journals and one from a public case library on the website of the Committee on Publication Ethics (COPE), the article defines the nature of duplicate content publications in multiple languages by comparing the content and presentation of texts, graphs, and tables and by conducting peer reviews to assess academic quality. Afterwards, it discusses the published ethical factors that need to be considered, the ethical issues that may arise in these three cases, and the rationale behind the implementation of specific handling measures. Finally, the article explores how to legally and reasonably uphold academic norms while safeguarding the interests of stakeholders. It provides policy recommendations for scientific journals from the perspectives of different stakeholders, suggesting that journals should clearly define copyright agreements for duplicate content publication in multiple languages, improve transparency requirements for multilingual publications by referencing international standards and practices, and enhance the visibility of Chinese-language publications while allowing copyright licences for other languages. This approach not only ensures academic integrity but also provides authors with a more flexible promotion platform and has a greater influence on the academic achievements of journals.