The rise of ”predatory journals”, also known as pseudo-scientific journals, poses a risk to the integrity of science and therefore medical communicators need to know about their practices. Upon receipt of a publication fee, predatory journals publish manuscripts regardless of their scientific merit, very often without any peer review, and without providing editorial services. To maximise profit, such journals disregard all aspects of scientific integrity and foster the dissemination of bad and bogus science, lobby materials, and conspiracy theories. Publishing in predatory journals can have dire consequences for authors, their careers, and the reputation of their institutions. Medical communicators can help authors avoid falling prey to predatory publishers.