In this study we investigated the effects of teaching on students' reading achievement. More specifically, based on a framework of reading instruction maximizing students' cognitive engagement in literacy learning, curricular and teaching variables, including aspects of word-recognition and comprehension instruction, approaches to teaching such as telling versus coaching, and the enabling of students' active versus passive responding to literacy activities, were investigated to explain growth on reading comprehension, fluency, and writing measures over a school year in grade 1-5 classrooms. Participants included 88 teachers and 9 randomly selected students per classroom in 9 high-poverty schools across the United States that were engaged in a literacy instruction reform project. Teachers were observed 3 times across the school year during a reading lesson. Hierarchical linear modeling showed that a number of teaching variables explained substantial variation in student growth on several measures of reading achievement. Looking across all of the data, the most consistent finding was that teachers who emphasized higher-order thinking, either through the questions they asked or the tasks they assigned, promoted greater reading growth among the 9 target students in their classrooms. We examine the results of our work in relation to a framework of teacher effectiveness maximizing students' cognitive engagement in literacy learning.