Seemingly unscrupulous entities, referred to as “predatory” journals, have appeared in scholarly publishing over the past decade. Predatory journals have been characterized as using questionable publishing practices and consequently, as publishing questionable research. At the outset of this thesis, such assertions were based on little evidence, making it difficult to understand how to identify a predatory journal and judge the extent of the potential problem they present. This thesis sought to: (1) determine how the apparent operations of predatory journals differ from their presumed legitimate counterparts; (2) to characterize the epidemiology and reporting of biomedical research published in predatory journals; and (3) to determine what, if any, guidance health research funders provide about selecting journals in which to publish funded research. Predatory journals appear to be distinct from presumed legitimate journals in several ways. For example, they lack descriptions of their editorial processes, ethical policies, and content preservation arrangements more often than presumed legitimate journals. Researchers, globally, have published clinical and preclinical studies reporting on millions of research subjects in predatory journals. Such content is poorly reported against established reporting guidelines; some of it originates from high profile institutions and is supported by well-known biomedical research funders. Most major funders propose journal publication as one way of achieving open access, yet few provide guidance on how to select a journal for this purpose. These thesis findings suggest that some features encountered on journals’ websites may signal potentially questionable journal practices. These features should be further evaluated to determine their accuracy in detecting predatory journals. Additionally, researchers may be sending research to predatory journals which may be of low quality, low priority, or unacceptable in legitimate journals. This is problematic because genuine research efforts/participant contributions may go undetected and never contribute to future knowledge generation. Future research ought to be done to determine why and how researchers, globally, choose where to publish. Research funders ought to agree on guidance and policies to ensure funded research can be found by others and is published in journals indicating basic standards for facilitating this.