Reading science text is not simply a process of translating printed symbols into meaning; it involves the interaction of the reader's prior knowledge, beliefs, concurrent experience, and the text in a sociocultural context to construct new meaning and understanding. The purposes of this study were to: explore the associations between metacognition (awareness and self-management) and science reading comprehension; investigate the effects of teaching science reading strategies on science reading metacognitive awareness, science reading metacognitive self-management, and science reading comprehension; and explore differential effects of science reading instruction on science reading metacognitive awareness, science reading metacognitive self-management, and science reading comprehension for specific reading ability and gender groups. The investigation used a single-group pretest/posttest case study design to capture the ecological validity of an intact classroom of 27 grade 7 students and their teacher. Results indicate significant correlations between metacognitive awareness and comprehension task success and a positive association between metacognitive self-management and comprehension task success and that a differential learning effect had taken place with lower ability readers and males gaining more from the instructional treatment. The results illustrate the impact that explicit instruction can have on science reading ability. Contains 55 references. (JRH)