The purpose of this article is to provide a review of empirical studies investigating the impact of professional learning communities (PLCs) on science teachers' practices and knowledge. Across 14 articles that satisfied the definition we embraced, most were devoted to the change in science teaching practices, disciplinary content knowledge (DCK) and pedagogical content knowledge (PCK) of K-12 science teachers. Although a small number of studies have implicit focus on comparing measures of student learning, we set out to examine the studies in science education and present how teachers engaged in PLCs focusing on examining and exploring strategies to promote student learning. Analysis of the related studies resulted in the following: PLCs can help teachers increase their PCK and DCK; increases in PCK and DCK may facilitate the change in teacher practices from traditional into more inquiry-based approaches; science teachers collaboratively focusing on student learning in PLCs are more likely to change their practice; and studies do not embrace student learning as an essential feature of PLCs. Methodological flaws and future directions along with implications for science teachers' professional development are discussed.