Purpose: This descriptive study investigates the genesis and change in physical educators' social media use for professional development and learning. Method: Data were collected through semistructured interviews with 48 physical educators who had actively used various social media professionally for an extended period of time. The data were analyzed inductively and aligned to the basic psychological needs defined by self-determination theory: relatedness, autonomy, and competence. Results: Building relationships with a trusted network of people and opportunities to express their autonomy were important drivers in the participants' genesis and continued use of social media. Developing competence at both the start and throughout their social media journey was also critical. Discussion/Conclusions: The findings provide a starting point for in-depth research on the motivational characteristics underpinning physical educators' reasons for starting and continuing to use social media for professional development and learning, and how these might change over time based on different psychological needs.