The purpose of this cross-case analysis is to illustrate how and why literacy was incorporated into science teaching and learning in three secondary classrooms. Research questions guiding the analysis include: (a) How were literacy events shaped by the teachers' philosophies about teaching science content and teaching students? and (b) How was literacy (reading, writing, and oral language) structured by the teachers and manifested in science lessons? The methodology of ethnography and the theoretical framework of symbolic interactionism were employed in the three studies on which the cross-case analysis was based. The researchers assumed the role of participant observers, collecting data over the period of 1 year in each of the three classrooms. Data, in the form of fieldnotes, interviews, and artifacts, were collected. In each study, data were analyzed using the constant comparative method (Glaser & Strauss, 1967) to determine patterns in the teachers' beliefs about learning and how these influenced their choice of literacy activities. The cross-case analysis was conducted to determine patterns across the three teachers and their classrooms. The findings from this analysis are used to compare how the teachers' philosophies of teaching science and their beliefs about how students learn influenced their use of literacy practices during lessons. Specifically, each teacher's use of literacy activities varied based on his or her beliefs about teaching science concepts. Furthermore, reading, writing, and oral language were important vehicles to learning science concepts within daily classroom activities in the three classrooms.