This qualitative study uses the theoretical concepts of identity, agency, and power to explore the ways in which students in their moment-to-moment interactions enact identities, agency, and power as they engage in the activity of writing and participate in a writing workshop. This research highlights what happens to writers as they engage in writing processes with one another and moves away from interpreting what happens between students as only cognitive or behavioral phenomenon. Additionally, through the lenses of identity, agency, and power, the complexity of what it means to be a writer in a writing workshop is made visible. Data for the study were collected over a five-month period and include observations of children participating in a third-grade writing workshop, written field notes, and detailed recording of the actions and interactions among the students as well as the teacher and students to capture the time, space, and participants' activity during the writing workshop. Whole class and small-group interactions were video and/or audiorecorded daily for later transcription, observation and reflection. Semi-structured informal interviews and informal talks with the students and the teachers were conducted and recorded on a regular basis, and the students' written work and other related artifacts were collected to examine the students' work as writers. The research reveals three major themes: 1) students enact multiple identities to serve a variety of purposes; 2) students enact agency in the ordinary and everyday practices of the writing workshop to change their present interactions, circumstances, and conditions; and 3) in their microlevel interactions, students enact macrolevel notions of power that shift classroom as well as peer relations. Additionally this study reveals the ways in which students use their written texts as evidence to substantiate the claims they are making about themselves and about others as learners and as people.