The term self-regulated is used to describe learners who have highly effective learning and work habits. They are successful in and beyond school. This investigation examines whether and how teachers, who are masters at supporting young students' development of self-regulated learning (SRL), can mentor student teachers to design tasks and develop practices that promote elementary school students' SRL. Nineteen student teachers were paired with 19 mentor teachers in a cohort that emphasized SRL theory and practice. In general, student teachers remained with the same mentors throughout their teacher education program and were supported by faculty associates and researchers who also had expertise in promoting SRL. Researchers observed mentor and student teachers teaching, videotaped professional seminars, and collected samples of student teachers' reflections, lesson plans and unit plans. Data indicate some student teachers designed tasks and implemented practices that promote SRL and that mentors' practices accounted for 20% of the variance observed in the student teachers' practices. Finally, the complexity of the tasks that mentors and student teachers designed was strongly predictive of opportunities for students to develop and engage in SRL.