High-quality, evidence-based professional development is essential to ensure that teachers obtain the knowledge, strategies and skills necessary to positively impact student learning. While the primary form of professional development, training has rarely been evaluated for quality beyond the satisfaction of those being trained. The Observation Checklist for High-Quality Professional Development Training (HQPD Checklist) was designed to measure observable indicators of effective professional development consistently. The HQPD Checklist is a valuable tool for professional development providers when designing and reflecting on training content, and for evaluators when monitoring the quality of professional development.