Fourth- and fifth-grade students' motivation and engagement during classroom discussions were investigated in 2 studies. Study 1 examined students' moment-by-moment engagement during collaborative peer-managed small-group discussions in comparison to conventional teacher-managed whole-class discussions. Study 2 evaluated the long term effects of discussions on self-reported motivation. Both studies showed that collaborative discussions produced greater interest and engagement than conventional discussions. Student self-ratings of engagement as well as adult ratings of engagement during a 6-min episode of one discussion had relatively high correlations with student self-reported interest and engagement several months later. Girls reported greater interest and engagement than boys in both conventional and collaborative discussions and were rated as more engaged by both themselves and adults; however, boys showed a greater boost in interest from collaborative discussions. Talkative children reported greater interest and engagement than less talkative children. Low-ability children put a higher value on discussion than high-ability children.