This study explored the impact of professional development workshops for online course design on faculty's pedagogical practices in online, face-to-face (f2f), and blended instructional modes. It specifically focused on trainings offered by the Quality Matters (QM) organization on a rubric for assessing quality in online course development. A mixed-methods analysis of survey data collected from 2,148 participants in QM workshops over a three-year period (2012-2015) demonstrated that, across all three teaching modes, participants revised learning objectives, improved course alignment, and paid greater attention to communication with students. Additional benefits from participating in QM training related to specific modalities. Common online and blended impacts included changes in assessment practices as well as in modifying course materials to be more compliant with accessibility standards. In f2f settings, frequent changes involved redesigning learning activities to increase learner-learner interaction.