Medical journals are fundamental elements in medical education, in professional life, in research and in academic careers. They communicate new scientific and clinical findings, legitimate and give credibility to biomedical and clinical investigation, are guarantors of the authors' intellectual property, are a useful forum for the discussion of relevant topics, distribute selected information to readers and are archives of their publications. Out of the numerous medical journals appeared before and during the XIXth Century, only 24 of them remain active until today and Revista Médica de Chile appears as number 20 in the list. Nowadays thousands of medical journals are published worldwide but only a small fraction are qualified as "mainstream journals", because they strictly apply an independent editorial process with clear criteria in manuscript selection based in external peer review, format requisites according to ICMJE Recommendations, are included in major databases, publish a high proportion of research articles, and other reasons. English language predominates in mainstream journals and abstracts in English become available in some databases. Electronic publications and open access are important tools to disseminate new information but the appearance of "predatory journals" is a threatening menace to the integrity of medical publications. Authors should identify and reject them. Some reflections may help those who intend to create new medical journals.