Increasing research on teacher professional development (TPD) has found teachers' self-reflection to be key for improving teaching effectiveness. Although video methodology, as often used in TPD, provides crucial insight concerning situated learning, teachers are often reticent to participate in TPD protocols due to discomfort over being videotaped. This longitudinal study explored emotion-related behaviors by assessing the nonverbal expressions exhibited by teachers during a 1-year video-based TPD program highlighting salient contributors to productive classroom dialogue. Six teachers were observed regarding bodily motion, facial expression, and eye contact, with results obtained across four workshops coded according to five types of emotions. The emotions of shame, defensiveness, and distraction appeared more often than did laughter and surprise, with the negative emotions found to decrease over time. This study highlights the importance of longitudinally evaluating teachers' emotional expressions during video-based TPD activities and continued efforts to encourage teacher participation in these pedagogical training opportunities.