This study investigates the influence of Green School designation on students' achievement in state-mandated standardized tests. Data were gathered 3 years pre- and post-Green schools designation, from test pass rates in reading and mathematics for Grade 5 and Grade 8 students, and from mathematics, English language arts, and biology scores for secondary students. Analysis indicated that Green School designation was positively correlated with standardized test pass rates in many schools and across subjects. Future work should investigate the mitigating impact of variables such as student socioeconomic status and level of teacher certification on student achievement in Green Schools.