In this study, the relationships among mathematical beliefs, sources of self-regulation, and achievement for university students enrolled in remedial mathematics were studied. Ninety-four students completed 2 surveys to measure mathematical beliefs and active, dynamic, and multiple-source self-regulation. Students who reported a more sophisticated belief about doing, validating, and learning mathematics were more likely to report greater frequency of all three types of self-regulation. The belief about the usefulness of mathematics and multiple-source self-regulation were reliable predictors of mathematics achievement. Multiple-source self-regulation also was a reliable predictor of academic achievement. Therefore, mathematics educators should acknowledge the relationship between achievement, either in mathematics or in academics in general, and both sophisticated mathematical beliefs and multiple-source (or wholetheme) self-regulation. (Contains 1 table.)