This study examined the effects of a graduate level, professional development (PD) course on teachers' perceptions, attitudes, self-efficacy, and behavioral intentions regarding the use of digital games in the classrooms, teacher involvement in educational game design, and constructionist gaming. Twenty-one teachers participated in the study. Both quantitative and qualitative data were collected from pre- and post-surveys and participants' reflections on major assignments. The results revealed significant changes in participants' perceptions, attitudes, and self-efficacy. At the end of the course, all participants believed that digital games could be helpful for students' learning and help students develop real-world skills, including higher-order thinking, problem solving, decision making, and collaboration skills. They also felt more comfortable using digital games in the classroom after completing the course. All participants agreed or strongly agreed that teachers should be involved in the process of educational game design. The participants also realized that constructionist gaming could provide an engaging and meaningful context where students can practice and develop real world skills. This study examined the impact of the PD experience on the participants' behavioral intentions beyond their perceptions and attitudes. The results showed that the PD experience had a positive influence on the participants' behavioral intentions. The findings of this study provide useful insights into teacher professional development.