The purpose of this study was to evaluate the effects of redundancy when learning from realistic science materials. Participants received instruction where redundancy was manipulated between text and diagrams with captions, text and diagrams, and text only. Participants reported levels of cognitive load, responded to questionnaire items and completed an achievement test. Findings indicated there were no significant differences in perceived mental effort between groups, though there were differences in experienced material difficulty. In contrast with the redundancy effect described by cognitive load theory, the manipulation of redundancy in lengthier text materials paired with diagrams did not affect performance on the achievement test.