Background: Adult-child relational interactions constitute an essential component of out-of-school-time programs, and training staff to effectively interact with children is key to improving program quality. Efficient staff training, that meets the limited time availability of out-of-school time staff, is particularly needed. Objective: This pilot study introduces Simple Interactions (SI), an innovative, strengths-based, and interaction-based professional development approach. Rather than attempting to teach generic competencies or targeting weakness areas for improvement, SI is designed to help program staff build from their strengths. Methods: In two cohorts over the course of 10 months, ten afterschool programs (N = 70 staff) participated in a pilot of SI. Program staff watched short video clips of themselves working with children and used the intuitive, 1-page SI Tool to guide discussion of adult-child interactions; specifically, connection (affective intune-ness), reciprocity (balanced roles of engagement), participation (involving all children), and progression (incremental challenge). Results: Results suggest that participants valued the professional development process, the strengths-based approach, and the use of self-video despite initial apprehension, and reported perceived improvements in their professional learning communities. Pre-post videos of Cohort 2 staff (n = 20), coded blind to time point (pre or post), indicate significant and substantive improvements in staff-child connection, reciprocity, and participation. Conclusion: These results support the use of this simple, practical, and potentially effective model of supporting quality improvement for and by local staff.