Students often struggle to comprehend complex text. In response, we conducted an initial, year-long study of Quality Talk, a teacher-facilitated, small-group discussion approach designed to enhance students' basic and high-level comprehension, in two 4th-grade classrooms. Specifically, teachers delivered instructional mini-lessons on discourse elements (e.g., questioning or argumentation) and conducted weekly text-based discussions in their language arts classes. Analysis of the videorecorded discussions showed decreases in teacher-initiated discourse elements indicating a release of responsibility to students, whereas students' discourse reflected increased critical-analytic thinking (e.g., elaborated explanations or exploratory talk). Importantly, statistically and practically significant increases were evidenced on written measures of students' basic and high-level comprehension, indicating the promise of small-group discourse as a way to foster individual student learning outcomes. [This paper was published in "American Educational Research Journal" v55 n5 p1113-1160 Oct 2018 (EJ1191768).]