Teachers play an influential role in children's health behaviors and there is evidence to support the need for children to be more physically active within preschool. To increase children's physical activity, teachers need to be intentional about promoting active play. To date, most research has focused on teachers' promotion of physical activity when children are outdoors or in physical education spaces. Therefore, the purpose of this study was to investigate preschool teachers' perceptions of physical activity promotion. This information may help to identify potential factors that could influence their behavioral intention to facilitate children's physical activity specifically within the indoor classroom. This study consisted of conducting semi-structured interviews with 25 preschool teachers throughout the state of Nebraska in the United States. A thematic analysis approach was used to reduce findings into themes and sub-themes. Validation of qualitative findings was conducted through peer debriefing, audit trail, and thick description. Five themes related to preschool teachers' perceptions and behavioral intention to use and promote physical activity within their classrooms emerged from their responses to interview questions. These themes were (1) defining physical activity, (2) social-emotional development, (3) teaching philosophy, (4) professional development, and (5) environmental barriers. The findings delineate factors that could be of focus for ongoing professional development and interventions to increase teachers' behavioral intention to facilitate children's physical activity. Topics of focus may include strategies to facilitate children's movement during indoor free play and reducing sedentary time, an emphasis on social-emotional benefits, and increasing teachers' self-efficacy to overcome barriers.