The purpose of this qualitative descriptive study was to explore how teachers perceived the experience of participating in the professional learning opportunity of collegial visits (CVs) as a facilitator of teacher self-efficacy (TSE) and collective teacher efficacy (CTE) in the Northeastern United States. The research questions that guided this study were: How do teachers perceive the experience of CVs, particularly with respect to their influence on teacher's own self-efficacy? How do teachers perceive the experience of CVs, particularly with respect to their influence on CTE? Semi-structured interviews and a focus group were utilized to collect data from 13 K-12 educators from urban and suburban public-school districts in the state of Connecticut. The theoretical foundation for this study was Bandura's Social Cognitive Theory and Triadic Reciprocal Causation Model. Thematic analysis was used to analyze the data and six themes emerged: cultural drivers and effects of CVs, impact of formal and informal learning experiences on teachers, teachers positive shift in opinions of CVs throughout implementation, teachers positive shift in emotions relative to experiences with CVs, teachers increased positive perceptions of teacher self-efficacy throughout implementation of CVs, and teachers increased positive perceptions of collective teacher efficacy throughout implementation of CVs. The conclusions highlight why CVs are an effective vehicle for professional learning for educators, administrators, and researchers. The results provide qualitative evidence demonstrating that CVs foster both TSE and CTE beliefs in educators that utilized this professional learning opportunity. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]