The roles of organizational and relational factors in regard to professional learning communities (PLCs) have been investigated by many, yet none have considered enabling school structures, trust, and collective efficacy as variables. We take a deeper look at the formal or organizational aspects of the school represented by enabling school structures, and the relational aspects characterized by collegial trust, trust in principal, and collective efficacy. Our empirical findings demonstrate the importance of establishing enabling school structures as an antecedent of PLCs. It is essential that school leaders provide enabling school structures in the form of leadership opportunities, shared decision making, and a hierarchy that supports teachers performing their jobs more effectively, as well as promoting healthy collegial interaction for teachers.