This paper is a response to a request asking for information on professional learning communities (PLCs) and their effect on teachers, students, and school culture. In order to respond to the request, a search for articles related to the subject was conducted using combinations of words such as "professional learning communities," "learning teams," "student outcomes," "school culture," "teacher impact," and "professional development." The majority of articles identified were case studies, school reform evaluations, and many anecdotal and "lessons learned" articles. In addition, reports from two other Evidence-Based Education Request Desk (EBE) requests were utilized to compile information--(1) Request #70, on PLCs and student achievement which provided a review of the literature, study summaries, and findings; and (2) Request #151, on PLCs and the influence of leadership. This response summarizes findings of the literature review as related to PLCs and school culture, teacher impact, and student achievement. A chart with a brief summary of each article and study findings has been provided. Request #151--which provides an overview of PLCs, potential barriers, and the role of leadership on PLCs--has also been included. (Contains 1 table.)