As a reflection of the value attached to interaction in L2 learning, pair and small-group activities have been integrated into different phases in the writing process. Focusing specifically on peer interaction during the planning and revision phases, this "In the Classroom" study explores the relationship between peer interaction and writing development. French L2 students (N = 45) in two classes completed two individual writing tasks (pre-test and post-test) and two practice writing tasks in which one class carried out pre-writing discussions (i.e., brainstorming and planning prior to writing) while the other class engaged in interactive revision (i.e., working together to revise a text). The students' tests were rated using an analytic rubric, and their conversations were coded in terms of what they had talked about while they were interacting (e.g., content and organization, grammar and lexis). Results indicated that students who carried out pre-writing discussions had higher grammar and lexis ratings at the post-test, while students in the interactive revision class showed no changes in their ratings. Analysis of the students' conversations indicated that they discussed content most frequently. Implications are discussed in terms of the pedagogical contribution of both activity types.