Although retrieval practice is a more effective learning strategy than restudy, students oftentimes prefer the latter. Previous studies have investigated this suboptimal decision at strategy level. The present study, however, focused on the learning task level: How perceived mental effort and perceived learning during task performance influence learning strategy decisions. Participants rated their mental effort and learning when memorizing anatomical image-name tasks, choosing either retrieval practice or restudy for each task. Moreover, the actual learning after each strategy was measured and presented as feedback. The results suggested that higher task-based perceived mental effort was directly related to reduced retrieval practice choice. Task-based perceived learning partially mediated the effect of task-based perceived mental effort on retrieval practice choice after feedback. Students chose retrieval practice more often after feedback. These findings underscore the importance of task-based perceived mental effort to learning strategy decisions and the potential of feedback to optimize these decisions.