Although successful learning in university education can be advanced by students' competence to self-regulate their learning, students often possess insufficient metacognitive regulation skills to regulate their learning adequately. The present study investigates changes in university students' adoption of metacognitive regulation after participating in reciprocal peer tutoring (RPT). A quasi-experimental pretest--posttest design was adopted, involving an experimental (n = 51) and two control groups; CG1 (n = 24) and CG2 (n = 22). Experimental students participated in a RPT intervention during a complete semester. Metacognitive regulation was assessed by means of think-aloud protocol analysis. Results indicate that RPT is promising to promote metacognitive regulation. Experimental students increasingly adopt monitoring, evaluation, and orientation and significantly evolve towards deep-level regulation from pretest to posttest. Except for an increased use of low-level comprehension monitoring, none of the evolutions in experimental students' regulation could be discerned for students in both control groups.