Analysis of discursive practices in science classrooms within STEM schools may provide meaningful information about the nature of these classrooms and, potentially, their uniqueness. Full descriptions of current practice can serve as a foundation for exploring the differences in instructional norms within STEM specialized schools and across science classrooms in general. In the current study, the authors address the following research questions: (1) What forms of discourse are prevalent in science classrooms in specialized STEM schools? (2) How do teachers drive classroom discourse through the types of questions they ask? and (3) How did students' perceptions of their own agency differ based on discursive classroom structures? Using a grounded theory approach, the authors investigated the discourse patterns present in a sample of science classes in specialized STEM high schools. Data across 6 specialized STEM schools, representing a diverse cross-section of school administrative structures and geographic locations within the continental United States, provide the opportunity to analyze these discursive practices. Classroom interactions between teachers and students were examined through an iterative review of observational and interview transcript data and constant comparison of emergent themes across episodes. Consistent patterns that emerged across STEM school sites within each of the major areas of analysis included: (1) authoritative vs. dialogic discourse; (2) teachers' use of questions to drive the discourse; and (3) students' strong sense of agency within classroom settings.