As part of a research project examining relationships between instructional practices and student cognitive and social outcomes in middle-school mathematics classes, external observers and students reported perceptions of teachers' instructional practices. The extent to which students in classrooms identified by external raters as reform-oriented actually perceive instruction in ways aligned with reform principles has not been established. A 25-item observation protocol aligned with the reform practices called for in the Standards of the National Council of Teachers of Mathematics (NCTM) was used to develop a quantitative profile of instructional practices across two lessons in each of 28 classes of 15 participating teachers. Students in each of the observed classes completed a 49-item survey of their perceptions of instructional practices. As items for both the observation protocol and Student Survey were designed to measure alignment with the same dimensions of reform practice, the convergence of these two data sets was examined as a means to confirm the observation ratings. The findings show moderately strong correlations between ratings of external observers and perceptions of sixth-grade students across three dimensions (pedagogy, tasks and mathematical interactions) of reform-oriented teacher practice in mathematics classrooms. Implications of these findings for future research are discussed.