A global survey of researchers was conducted to gather perceptions on the prevalence and impact of predatory academic journals and conferences. The survey was open and inclusive in nature, with 1872 researchers, from a wide array of geographic regions, disciplines and academic career stages, voluntarily participating. Both quantitative and qualitative data were collected and analysed. The survey revealed that over 80% (1537 of 1859) of respondents perceive predatory practices are already a serious problem or on the rise in their country of work, and risk infiltrating and undermining the research enterprise if left unchallenged. At least 24% (445 of 1872) of respondents admitted they had already published in a predatory journal, participated in a predatory conference, or did not know if they had. Over 87% of respondents who had published (174 of 199) or participated (60 of 64) indicated that a lack of awareness of predatory practices was the main reason. Those in lower-middle and upper-middle-income countries were more likely to indicate they had engaged in these activities than those in high-income ones, with some disciplines appearing to engage more than others. Individual impact was mixed: some indicated no impact while others noted a range of negative and detrimental feelings.