This article examines physical education pre-service teachers’ (PTs) self-efficacy and practicum experiences as self-efficacy sources through a mixed-method approach. Results showed a stronger self-efficacy in the relationship with students and discipline promotion. Lower self-efficacy was linked to instructional strategies. PTs with higher self-efficacy reported professional experiences before practicum as mastery experiences. During the practicum they highlighted as mastery experiences: classes’ characteristics, planning and teaching practice; lesson observation as vicarious experiences; and post-lesson conversations as verbal persuasion. PTs with lower self-efficacy reported classes’ characteristics and teaching practice as failure experiences.