Reading and writing are central to the conception of science and the work of scientists. While recent scholarship on science literacy suggests the benefits of integrating reading and writing in science teaching, less is known about the extent to which science teachers implement such integration. This naturalistic study examines two sixth-grade science teachers' beliefs about reading and writing in science and the type and frequency of reading and writing activities they assigned in three different classes (regular, gifted, and magnet). Each class was observed twice per week for nine weeks. Data sources include classroom observation field notes, interviews with the teachers, and classroom reading/writing artifacts. The observations were analyzed and coded for minutes of class time used for reading and writing activities as well as the materials used. Interview transcripts were coded and analyzed for beliefs related to reading and writing. Findings indicate that teachers believe learning strategies are important for content delivery, which included a large amount reading and writing time in class that was spent copying notes and completing worksheets. Although vocabulary instruction was given more attention, there was little to no textbook use, virtually no instruction in reading or writing, and little differentiation in materials or instruction among the regular, gifted and magnet classes. The teacher participants perceived that student ability stands as a powerful contributing factor in the type of achievement possible for magnet, gifted, and regular classes. The results are discouraging considering decades of research on literacy integration in science and ten years of the Common Core State Standards and the Next Generation Science Standards. Is there more that schools of education or directors of professional development should do to encourage literacy integration in science classes? [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]