Open science (OS) practices have gained broad recognition in recent years, and many surveys have examined researchers’ perspectives on OS. However, these studies have primarily focused on samples from the Global North, with limited representation of the Global South. Here we present survey data from 371 researchers in China and Nigeria, examining their awareness and lifetime usage rates of OS practices, attitudes and intentions towards OS, perceived barriers, as well as questionable research practices (QRPs). Respondents from both countries have been aware of OS practices and expressed strong support for them, but with reserved intentions and low lifetime usage rates. The major barriers included high time costs, insufficient incentives, lack of training and guidance, and technical and infrastructural constraints. Furthermore, consistent with the previous surveys, many common QRPs, such as continuing data collection after seeing the results, were reported to be widespread. These results indicate that while researchers in China and Nigeria support OS at large, they are facing substantial barriers in translating positive attitudes into actions. Importantly, our survey revealed that education and training are still needed to dispel myths related to OS practices to pave the way for their adoptions. Collectively, our findings highlight the need for both top-down approaches (e.g., policy) and bottom-up initiatives (e.g., grassroots community-building) to promote OS in Global South.