The current study aims to understand the development of students' professional self-regulation during pedagogical practice. Fifty participants of this study were fourth-year students of the Ternopil Volodymyr Hnatiuk National Pedagogical University, Ukraine. The following questions were considered: Has any certain level of professional self-regulation been formed before practice? Will it increase during the pedagogical practice? Is it possible to influence the process of formation of future teachers' professional self-regulation during the pedagogical practice by offering them specific tasks? To diagnose the formation of self-regulatory mechanisms of students during pedagogical practice, we propose to use the phenomenon of readiness (namely, how to determine, characterize, and measure it). The research was carried out using the methods of questionnaires, conceptual dictionary, and expert evaluation. The level of readiness for professional self-regulation in most respondents has increased from the "lower" to the "upper" limit within the Medium level. The results contribute to the conclusion that professional self-regulation of a teacher as a necessary component of future professional activity is developed effectively during pedagogical practice; moreover, this process is intensified by the implementation of assignments aimed at understanding self-regulatory mechanisms.