The purpose of this study was to explore whether conceptual change predicted emotional and attitudinal change while learning about genetically modified foods (GMFs). Participants were 322 college students; half read a refutation text designed to shift conceptual knowledge, emotions, and attitudes, while the other half served as a control group. The results suggest that the refutation text effectively facilitated change in conceptual knowledge, emotions, and attitudes. The hypothesized relationship among the variables was explored using structural equation modeling. The analysis showed that when participants experienced knowledge change toward more scientifically accepted conceptions of GMFs, their emotions became more positive and less negative, which predicted a subsequent shift toward more-positive attitudes. The results suggest that change in emotions mediates the relationship between conceptual and attitudinal change. Several theoretical and practical implications are discussed including the impact that these findings may have on science education.