Although encouraging student creativity is a commonly recognised goal of STEM education, there is a lack of research in this area. In this study, the effects of epistemic beliefs on STEM creativity and the mediation of intellectual risk-taking were investigated. The subjects were 461 primary students in Hong Kong. The findings revealed that (i) intellectual risk-taking was a significant and positive predictor of STEM creativity; (ii) the certainty and justification dimensions of epistemic beliefs had direct, negative and significant impacts on STEM creativity; and (iii) the complexity dimension of epistemic beliefs had both direct and indirect significantly positive impacts on STEM creativity, and the indirect impacts were mediated by intellectual risk-taking. This study revealed the complicated relationships between different orientations in epistemic beliefs and STEM creativity, which include both constraining and facilitating effects, and both direct and indirect impacts. We argue that although reducing naïve and relativistic epistemic beliefs is essential for the development of creativity in STEM education, the effects of cultivating mature epistemic beliefs may not be sufficient. Further direct and explicit approaches are required to more effectively enhance students' STEM creativity.