Abstract: Accurate monitoring is important, as it guides subsequent control of learning. With multimedia, learners often overestimate their learning. Retrieval practice provides insight into one’s understanding; still, it might not improve monitoring. In an online experiment with two groups, participants ( N = 146) performed retrieval practice while studying multimedia instructions. We investigated whether monitoring prompts affect metacognitive accuracy, subsequent learning behavior, and performance: One group repeatedly received prompts, whereas a control group did not. After studying, both groups provided metacognitive judgments for a subsequent posttest. As expected, learners in the control group were overconfident about their learning; however, unexpectedly, prompted learners were also overconfident and did not differ from the control group. Nevertheless, prompted learners provided longer answers to retrieval tasks, which increased their posttest performance (indirect mediation). We observed no mediation for learning time or retrieval performance, although retrieval performance did relate to posttest performance. The results suggest that monitoring prompts do not improve metacognitive accuracy per se but might improve learning outcomes by controlling subsequent learning.