Self-efficacy beliefs are evaluations people make about their capability to handle specific, future challenges. Self-efficacy belief levels predict actual success. Public school principals face ever-changing challenges. Understanding school principal self-efficacy beliefs and supporting the development of these beliefs is one way supervisors can help the future effectiveness of school principals. There are four main sources of information used to develop self-efficacy beliefs. These four sources of information are: mastery learning, vicarious learning, verbal persuasion, and emotional arousal. This multiple case study research examined the factors that influenced self-efficacy beliefs of elementary school principals prior to facing a personally meaningful challenge. The overall research question was: What Factors Attend to the Domains of Self-Efficacy Belief Formation in School Principals? The purpose of the research was to understand what information influenced the mindsets of principals as they formed their initial self-efficacy beliefs prior to facing a personally meaningful challenge.