Synthesizers of evidence are increasingly likely to encounter studies published in predatory journals during the evidence synthesis process. The evidence synthesis discipline is uniquely positioned to encounter novel concerns associated with predatory journals. The objective of this research was to explore the attitudes, opinions, and experiences of experts in the synthesis of evidence regarding predatory journals. Employing a descriptive survey-based cross-sectional study design, these experts were asked a series of questions regarding predatory journals to explore these attitudes, opinions, and experiences. Two hundred and sixty four evidence synthesis experts responded to this survey. Most respondents agreed with the definition of a predatory journal (86%), however several (19%) responded that this definition was difficult to apply practically. Many respondents believed that studies published in predatory journals are still eligible for inclusion into an evidence synthesis project. However, this was only after the study had been determined to be 'high-quality' (39%) or if the results were validated (13%). While many respondents could identify common characteristics of these journals, there was still hesitancy regarding the appropriate methods to follow when considering including these studies into an evidence synthesis project.