In a first-semester general chemistry course, metacognitive training was implemented as part of an online homework system. Students completed weekly quizzes and multiple practice tests to regularly assess their abilities on the chemistry principles. Before taking these assessments, students predicted their score, receiving feedback after completing the assessment on their prediction accuracy. They also received detailed information regarding their ability for each assessment topic and used this information to create a future study plan. During this study plan, students indicated their general ability by chemistry topic and selected areas they would focus their studying upon. A control section completed the same assessments and received the same feedback of ability by topic, but students did not predict scores or create study plans. Results indicate identical initial assessment performance between the two chemistry course sections. However, metacognitive training resulted in improved assessment performance on each subsequent midterm exam and on the American Chemical Society (ACS) general chemistry final exam. After factoring out the effect of teacher differences, metacognitive training improved student ACS final exam average performance by approximately 4% when compared to the control section. Additionally, metacognitive training targeted the bottom quartile of the course by improving their ACS final exam average performance by approximately 10% when compared to the control section.