Teachers critically need classroom management skills. To develop these skills, teachers need high-quality professional development (PD). To support teachers, schools need practical tools for assessing the effects of PD on teachers' use of classroom management practices. The adapted alternating treatments design (AATD) may be a tool for this purpose. We conducted an initial pilot investigation testing the potential of AATDs to evaluate the effects of PD on teachers' use of classroom management practices for eight Pre-K-12 teachers. We successfully used AATDs to evaluate PD effects in all cases across two phases of PD (online module instruction, online module + peer coaching). Results suggest the potential promise of using AATDs to evaluate the effects of PD on teachers' use of classroom management practices. Results also showed didactic training alone was often insufficient to increase use of practices, whereas peer coaching was effective in increasing use of at least one practice for all teachers.