Educators in a local southeastern U.S. elementary school are concerned that English language learners are not meeting mandated mathematics achievement requirements on state tests. This case study explored how 12 Grades 3 through 5 English for speakers of other language (ESOL) teachers who were purposely selected, described the push-in program model for mathematics instruction. The study examined how the teachers delivered the push-in ESOL program and the instructional strategies they used. The conceptual framework was guided by Bandura's social learning theory and language acquisition theories and informed by Krashen's second language acquisition theory, Cummins's language proficiency theory, and Collier's second language acquisition theory. Observations, interviews, and documents were analyzed using inductive coding to identify themes: teachers build success through knowledge of second language acquisition, teachers build success by using knowledge of students' cultures and background, teachers build success by being highly qualified and participating in professional development, teachers build success through collaboration, and teachers struggle to meet the needs of all students. Additional themes emerged that informed the subquestions of how teachers delivered instruction to ESOL students in the push-in program: teachers create a positive and supportive learning environment, teachers use research-based instructional strategies and teachers use a variety of data to promote student learning. The project developed from the findings is a 3-day professional development seminar for ESOL teachers and classroom teachers designed to build coteaching skills. The expected implication for social change is the development of a collaborative environment within the school that will promote student achievement.