Problem-based learning (PBL) is an instructional method that offers students the opportunity to develop self-regulatory strategies as an explicit learning outcome. As a multifaceted PBL environment, the guidance of tutors is important to students as they develop self-regulatory learning (SRL) skills and self-efficacy, the most focused motivational element in SRL. The present study examines the relationship between academic achievement and PBL self-efficacy levels, as well as the role played by tutors. A cross-sectional study was conducted with third-year medical students (n = 257; 75%). The SRL perception (SRLP) scale, the selfefficacy for PBL scale (SPBL), tutor evaluation scale (TES), and an achievement test were used to gather data in this study. In every scale, participant scores were higher than the midpoint, which is 3. There were positive correlations between SRL, self-efficacy, and the tutoring scores of tutors. As the correlation between SRLP and achievement was not significant, achievement was removed from the regression equation, and only SPBL and TES results were used. The results of the regression analysis indicated that SPBL and TES explained 36% of the variance. The level of self-efficacy in PBL predicted the students' SRL abilities, as did tutor evaluations. The findings show that students used their SRL skills and had beliefs about their ability to learn effectively in the PBL context. Both the tutors' tutoring skills and the students' self-efficacy made important contributions to improving the students' self-regulated learning skills.