The aim of my study was to explore the nature of changes in pre-service science teachers' (PSTs') self-efficacy beliefs toward science teaching through a mixed-methods approach. Thirty-six participants enrolled in a science methods course that included a collaborative peer microteaching ("Cope-M"). Participants' science teaching self-efficacy beliefs were measured using paired t-test procedures on Science Teaching Efficacy Beliefs Instrument-B before and after the course. Additionally, structured interviews were conducted with six PSTs. After the "Cope-M" process, participants continued their education in two subsequent terms, spending time observing professional teaching practices and being involved in science teaching practice in a local middle school. Finally, besides administering the self-efficacy scale again, a questionnaire regarding final perceptions of science teaching and microteaching was administered. Results suggested microteaching sessions provided a supportive and rich environment to develop cognitive, affective, and psychomotor skills in terms of professional teacher behaviors. Moreover, the microteaching sessions provided a supportive medium for enhancing science teaching self-efficacy beliefs.