Whereas Professional Learning Communities (PLCs) are a frequently applied professional learning tool in education, their use is often limited to an application among (a) teachers and (b) within-schools. This article contributes to the nascent research evidence on PLC usage for principal professional learning. As outcomes align with PLCs’ phased development, this article grasps the learning processes that unfold, the catalyst states that emerge and the overarching role that a process coach can adopt in this collective learning effort. Three distinct PLCs comprising of Flemish secondary school principals were systematically observed over the course of one to two years. In interviews and questionnaires, members (n = 14) reported on their experience with PLC activities, group dynamics and their personal professional well-being. Networked learning proved a worthwhile method as positive outcomes of PLC participation were predominantly found in a perceived augmentation of professional well-being and the acquisition of inspiration and ideas. Actual co-construction among principal participants appeared harder to establish as several organisational, group developmental and leadership prerequisites were found to apply. As this study was based on three in-depth case studies, it remains to be confirmed whether its conclusions apply to all school principals in Flanders and can be generalised to their counterparts internationally.