Reading aloud to students in preschool and the early grades is ubiquitous in American classrooms and considerable research has been conducted on read aloud practices (Karweit & Wasik, 1996; Morrow & Brittain, 2003; Van Kleeck, Stahl, & Bauer, 2003; Varelas & Pappas, 2006; Wilkinson & Silliman, 2000). Compelling evidence indicates that explicit instruction has a positive impact on a range of student academic outcomes, particularly for students who are at-risk for academic difficulties (Gersten, 1998; Swanson & Hoskyn, 1998; Vaughn, Gersten, & Chard, 2000). The purpose of this study is to examine the interaction effect of the quality of instructional delivery on student vocabulary and reading comprehension. In order to create and sustain gains in comprehension, the intervention focused on teaching students how to use the same sorts of strategies to comprehend text when their teachers read to them in first grade that they could use to read text on their own. A total of 39 first-grade classrooms from 12 schools in the Mid-Atlantic region were randomly assigned to an intervention or comparison condition. The read aloud intervention consisted of 12 narrative books and 12 expository books related to animals and taught over a period of 19 weeks. The findings from the study suggest that the effect of read alouds in first grade depend on the delivery of instruction. Instructional quality in the context of this study was defined as teacher ability to deliver an explicit instruction with fidelity. This finding is important given the current pressure teachers face to improve student outcomes.