Oregon Mathematics, Engineering, Science Achievement (MESA) focuses its afterschool programs with middle and high school students on inventions that address key problems in developing countries, such as sustainable lighting, water transportation, water filtration, and prosthetics. With the support of a grant from the Oregon Community Foundation, MESA expanded its afterschool program to four Salem-Keizer Public Schools middle schools in the 2014/15 and 2015/16 school years. The goal of this expansion was to help underrepresented minority and low income students achieve scholastic success, leadership skills, and social support for college enrollment through (1) afterschool STEM (science, technology, engineering and math) programs led by teachers from the school served; (2) science and technology competitions; (3) family involvement and advocacy; and (4) mentorship by local college students. At the request of MESA, researchers at Education Northwest conducted an evaluation of the impact of MESA's afterschool program on the educational outcomes of MESA participants in Salem-Keizer middle schools. To do this, we collected a student-level dataset from Salem-Keizer and examined how participation in MESA affected student outcomes. Specifically, we used statistical methods to identify a comparable group of students with similar characteristics but who did not participate in the MESA program. We then compared these students' school attendance, test performance, grades, and behavior to those of MESA students. The study found that MESA students had higher grades in science and mathematics classes than their peers.