Constructivist "theories" of teaching and learning have continued to grow in popularity among educational policy makers, but it is far less certain whether constructivist teaching "practices" have found their way into most classrooms. Textbooks, arguably the most important non-personnel instructional resource in classrooms, heavily influence what teachers teach and how, but how much textbooks support constructivist pedagogy in particular is unclear. The purpose of this study is to assess constructivist practices in classrooms by exploring the opinions of Saudi Arabian teachers about the degree to which their textbooks adopt and support principles of social constructivism and the degree to which these principles vary by subject matter specialization. We gather information on 31 "characteristics of textbooks" identified as "constructivist" from 231 intermediate grade teachers across multiple subject areas in Riyadh. Teachers' responses to items framed on a Likert scale were frequency analyzed, and degrees of difference associated with teacher subject matter background were tested using one-way analysis of variance. Results indicated that (1) textbooks only minimally support constructivist pedagogical practices and (2) textbook emphases on constructivist pedagogical practices do not vary significantly by subject matter area. Despite extensive policy support to the contrary, Saudi Arabian textbooks foster at best only very modest levels of constructivist practices in classrooms. This effect was consistent across different subject matter fields. Implications for educational policy makers and for future research are discussed.