This research was designed to investigate the effectiveness of using the think-aloud strategy to improve the reading comprehension in the content area of science. Based on state standards assessments, many early elementary grade students who were considered fluent readers struggled with evaluative science comprehension. In this quasi-experimental case study, the researcher used a self-created set of lessons using the think-aloud strategy for science as the intervention. The target group of this study consisted of two classrooms totaling 48 first-grade students identified as regular education or gifted. The treatment group received instruction using the think-aloud strategy during the science block. The control group received the regular instruction of the school district's science curriculum without the think-aloud strategy being incorporated. Results of using the think-aloud strategy during science instruction significantly increases a students' comprehension of science text. Findings from this study assisted with improving student learning by providing teachers with an instructional method (the think-aloud strategy) in the science-content area and in enabling every student to experience a certain degree of success in the evaluative comprehension of science text. The findings from this study were useful to teachers, administrators, school district personnel, and curriculum developers to improve comprehension levels in all students by implementing the think-aloud strategy.