Over the last two decades many school districts have developed professional learning communities (PLCs) as a means of unifying teachers within school organizations toward common goals and collaborative efforts. This study purports that there are certain enabling school structures that influence the success or failure of PLCs implementation. Hoy and Sweetland summarize that "school structures vary along a continuum from enabling at one extreme to hindering at the other" (Hoy, 2002, p. 88). Other key aspects of PLCs relate to the role of collegial trust, teacher's collegial trust, and trust in principal. One of the assumptions underlying the theoretical framework is that trust is an essential aspect of building a PLC. While there is emerging research about trust and enabling school structures, none has been linked to PLCs. This study will examine enabling school structures, collegial trust, and trust in principal in context to professional learning communities, which are also called communities of learning, teacher communities, and communities of continuous inquiry and improvement.