This study examined existing data from 2007-09 to measure the impact of professional learning communities and teacher leaders to improve student writing. The researcher/principal of the subject high school implemented and studied the impact of a restructuring plan in a mixed methods study. The measures in this study examined the collective summative results of l0th grade student writing throughout the 2008-09 school year. Teacher and teacher leader questionnaires, observation, field notes and student writing assessments were examined. The California High School Exit Exam Writing Essay scores from the 2007 and 2009 cohort were compared to determine if writing treatments implemented in 2009 impacted student writing. Significant findings using ANOVA suggest that teacher leaders facilitating professional learning communities made a positive impact on student achievement in writing. The findings of this study may provide future educators with more information about the role that teacher leaders play in facilitating professional learning communities.