The plight of students learning language simultaneously with content material, particularly math, spurred this study of the power of socioculturally based pedagogy, such as Instructional Conversation (IC), to increase Spanish-speaking minority students 'acquisition of English math lexicon and concepts. This article describes a series of four ICs taught by a novice teacher. The ICs were designed to promote interaction about math concepts in small groups of seventh-grade students who were ordinarily excluded from classroom participation by their regular teacher. In keeping with sociocultural theory, the IC teacher assisted students' conversation on math topics using visual stimuli, joint productive activity, and teaching that regularly urged students toward language expression on math topics. After describing the features of IC pedagogy, this paper analyzes the transcripts of the ICs using quantitative and discourse analysis. Measures of teacher and student percentages of talk, use of content lexicon, and appropriacy of student talk were obtained. Results indicated that all the students participated comfortably in academic conversation using math lexicon with increasing appropriacy and focus. Intersubjectivity emerged in the conversations and was apparently built on the students' and teacher's similar and shared experience in constructive social interaction about math. Students' participation in IC increased dramatically and stabilized across the four ICs, indicating the usefulness of this pedagogy to include often excluded language minority students in classroom interaction.