This study used data collected from in-service early childhood teachers enrolled in a summer pre-kindergarten endorsement program hosted at a large urban university in Middle Tennessee. Data were also collected from pre-service teachers enrolled in three different courses in an Education Preparation Program, at the same institution. The independent variables included the participants’ characteristics (i.e., number of years of teaching experience and amount of professional development), and the teachers’ attitudes and their personal beliefs exhibited in the classroom. The dependent variable was the teachers’ knowledge of self-regulation. The results suggested that the level of the teachers’ knowledge of self-regulation was impacted by the number of years of teaching experience and the amount of relevant professional development/training. The level of knowledge of self-regulation, however, had no impact on teachers’ attitudes and personal beliefs in the classroom. (author abstract)