This study evaluated the effectiveness of the "simSchool" (v.1) simulation as a tool for preparing student teachers for actual classroom teaching. Twenty-two student teachers used the simulation for a practice session and two test sessions; data included objective performance statistics generated by the simulation program, self-rated performance data, and qualitative opinions and perceptions from participants. Participants' scores for their simulated students' learning significantly improved between practice and actual simulation sessions with one student, but their learning scores significantly decreased as complexity increased between sessions with one student and five students. Task appropriateness scores increased with practice. Participant ratings indicated that overall they found "simSchool" to be a helpful tool for learning about classroom teaching and identified shortcomings in the user interface and simulation organization that should be corrected to improve its effectiveness. Results show promise for the use of the simulation to augment teacher training programs before the actual classroom teaching experience.