'Continuous effort, not strength or intelligence, is the key to understanding our potential.' Margaret J Wheatley. The focus of any academic or research author is to share his or her findings, and to gain respect and reward for publishing. The ideal journal is one that not only publishes an article quickly but also helps the author to improve the article before publication through peer review, selects only the best research so that the author's article lies alongside other high quality articles, and provides maximum (and long-term) visibility and access to the article. Unfortunately, in the real world, authors need to make tradeoffs between high quality journals, those that work quickly, those that are willing to accept the article and those that provide the best access. Into this mix has come the potential of open access as a means of increasing visibility: journals publish the article without a subscription barrier so anyone, anywhere, can read the article. However, the growth of open access (pushed by institutions, grant bodies and governments as a means of improving human health and knowledge) has come with some unforeseen consequences. In this article, Jeffrey Beall discusses one recent phenomenon that has arisen from the open access movement: that of 'predatory publishers'. These are individuals or companies that use the open access financial system (author pays, rather than library subscribes) to defraud authors and readers by promising reputable publishing platforms but delivering nothing of the sort. They frequently have imaginary editorial boards, do not operate any peer review or quality control, are unclear about payment requirements and opaque about ownership or location, include plagiarised content and publish whatever somebody will pay them to publish. Predatory publishers generally make false promises to authors and behave unethically. They also undermine the scholarly information and publishing environment with a deluge of poor quality, unchecked and invalidated articles often published on temporary sites, thus losing the scholarly record. Jeffrey Beall, a librarian in Denver, US, has watched the rise of such fraudulent practice, and manages a blog site that names publishers and journals that he has identified as predatory. While Beall's lists can provide librarians and knowledgeable authors with information on which journals and publishers to be cautious about, several legitimate publishers, library groups and others have joined forces to educate and inform authors in what to look for when selecting journals to publish in (or read). This initiative, called Think. Check. Submit. (http://thinkchecksubmit.org/), was launched in the latter half of 2015 and hopes to raise awareness of disreputable journals while clearly separating them from valid, high quality, open access journals (of which there are many). PIPPA SMART Guest Editor.