In this research, two questions related to arts integration are studied: First, the extent to which sixth and seventh grade students' language arts and mathematics performance, as well as their engagement with school are positively impacted by classroom settings in which theater strategies are integrated into language arts instruction; and second, the extent to which students are able to sustain their learning gains in language arts once they return to a traditional language arts learning environment. The research is based on a study in which four schools in an urban school district that has a high poverty level, were randomly selected to participate in a federally funded arts integration project; and four schools were randomly assigned to the control group. A total of 28 classrooms and 1020 students were in the study sample. The findings indicate that being in an arts-integrated classroom increased the odds of students passing the state assessment in language arts by 77 percent and by 42% in mathematics. Students who exited the arts integrated project were able to sustain their learning gains once they returned to a traditional instructional setting. For example, seventy-eight% of eighth graders whose language arts instruction as seventh graders included the use of theater strategies were proficient in language arts on the eighth-grade assessment, compared to 69% of students who were instructed using traditional pedagogy. (Contains 3 tables.)