Despite widespread recognition of the importance of reflective practice in the field of infant mental health, little quantitative research exists regarding the impact of reflective supervision on professionals' self-efficacy, job satisfaction, and work-related stress. Thirty-three early childhood interventionists received approximately 9 months of reflective supervision and completed pre- and post-assessments of their job-related stress and self-efficacy using a modified version of the Reflective Supervision Self-Efficacy Scales for Supervisees (S. Shea, S. Goldberg, & D.J. Weatherston, 2012). At the post-assessment, participants also rated their overall experience of reflective supervision. Reported self-efficacy increased significantly from pre- to post-assessment, and participants reported a positive overall impact of reflective supervision with respect to a variety of indices, such as job satisfaction, professional development, and the ability to cope with job-related stress. These results provide necessary quantitative data demonstrating a positive impact of reflective supervision on early childhood professionals and suggest the value of reflective supervision for supporting workforce development.