This study examined the effects of a school-wide Direct Instruction reading program implementation through measurement of student reading achievement pre and post-implementation and changes in DI teacher expectations of student academic performance. A low-SES elementary school served as the setting for this study, and DI curricula implemented included Language for Learning, Reading Mastery, and Corrective Reading. As a comparison, student academic performance expectations of teachers in non-DI schools were measured. DI teachers completed the Teacher Questionnaire (created by the authors), and were asked to complete 17 items that presented possible academic performance expectations that teachers may have for their students. Non-DI teachers were presented with the Student Activity Analysis Form (SAAF), which introduced a passage from the Reading Mastery program and asked teachers to make judgments regarding a) the percentage of their students who would be able to read the passage with comprehension, and b) the grade-level appropriateness of the reading passage for high ability, average ability, and low ability students. Results indicate substantially more students who received the DI reading curricula passed the state reading assessment, increasing from 24% to 70.8% of students across 7 years. With regards to teacher perceptions of student academic achievement, DI teacher expectations significantly increased after DI implementation. In comparison, non-DI teachers’ achievement expectations significantly underestimated the level and rate of student reading performance. (Copyright © 2011, National Institute for Direct Instruction (NIFDI). All rights reserved).