We aimed to investigate how metacognitive regulation is characterised during collaborative learning in a higher education reciprocal peer tutoring (RPT) setting. Sixty-four Educational Sciences students participated in a semester-long RPT-intervention and tutored one another in small groups of six. All sessions of five randomly selected RPT-groups were videotaped (70 h of video recordings). Analyses were focussed on identifying time-bound evolutions with regard to (a) the frequency of occurrence of metacognitive regulation, (b) the low-/deep-level approach to regulation, and (c) the initiative (by tutors/tutees) for metacognitive regulation. Logistic regression models allowing change points were adopted to study evolutions over time. The results indicated that RPT-groups increasingly adopt metacognitive regulation (i.e. orientation and evaluation) as the RPT-intervention progressed. Regarding RPT-groups' regulative approach, the results revealed a significant evolution towards deep-level metacognitive regulation (i.e. orientation and monitoring), despite a dominant adoption of low-level regulation strategies. With regard to the initiative, the results demonstrated that tutees started to initiate RPT-groups' monitoring significantly more frequently as they became familiar with the RPT-setting. Orientation, planning, and evaluation remained tutor-centred responsibilities.