College students' metacognitive self-assessments before and after tests were examined in relation to personality and study time. Instead of using laboratory learning, this study is the first to use actual classroom learning and testing across a period of several months to study the dynamic relation between personality, study time, and cognitive self-assessments. The findings revealed that competitive students gave higher metacognitive self-assessments than less competitive students and that students who had a tendency to show concern about others' opinions spent more time studying for tests. In addition, students were able to use previous testing experience to adjust their study time and metacognitive self-evaluations correspondingly on later tests. High self-monitors were especially more likely to use feedback from earlier tests to alter metacognitive self-judgments.