This manuscript builds on the previous reviews of professional learning communities (PLCs), using 10 empirical international research studies to present the impact of PLCs on teacher practice and student learning. The results showed that PLC studies that embrace collaboration and focus on student learning reported improved teacher practice and student learning. We highlighted some methodological issues to take into account before validating the reported PLC impact. A path model to study PLC impact and three key features of PLCs that would produce improvements in teacher practice and student learning are suggested along with discussion on international aspect of PLCs.