Predatory journals cannot be considered trustworthy because of their lack of transparency and scientific rigor, for example within the peer review process. This phenomenon began to spread with the advent of open access journals and takes advantage of its economic model. Since a unanimous definition of predatory journal is lacking, it is difficult for a potential author of scientific articles to distinguish predatory journals from those respectful of the internationally shared best publication practices. To do so, it is useful to know the criteria by which scholarly journals are evaluated and considered, for instance for their indexing in bibliographic and bibliometric databases. These criteria relate primarily to the content of the journal, the internal organization of the journal and its business model, and the policies adopted to ensure research integrity, and are largely or entirely absent in predatory journals: the analysis of these aspects on journal websites can be crucial in order to choose the publishing venue for the publication of one's work.