Retrieval practice has been shown to produce powerful learning gains in laboratory experiments but has seldom been explored in classrooms as a means of enhancing students' learning of their course-relevant material. Furthermore, research is lacking concerning the role of individual differences in learning from retrieval. The current study explored the effects of retrieval in a large undergraduate introductory biology course as a function of individual differences in student achievement. Students completed in-class exercises that required them to retrieve course information (e.g., recalling definitions for terms and labeling diagrams) followed by feedback or to simply copy the information without retrieving it. A later quiz over the information showed that high-performing students benefited more from retrieving than copying, whereas middle- and low-performing students benefited more from copying than retrieving. When asked to predict their quiz scores following the in-class exercises, high-performers demonstrated better overall metacognitive calibration compared to middle- or low-performers. These results highlight the importance of individual differences in learning from retrieval and encourage future research using course-relevant material to consider the role of student achievement in classroom-based interventions.