This qualitative classroom-based study investigated the writing practices, choices, and reflections of Latinx high school students during an instructional unit on writing testimonio. The study was grounded in a sociocultural theory of writing and draws from LatCrit and testimonio research to understand how writing about self as testimonio shapes the writing practices Latinx, urban mujeres. The study took place in an eleventh grade class at an urban charter school in a major urban center in the southwest. Data collection included writing samples, interviews, participant observer memos, and field notes. Analysis was conducted through a testimonio and narrative analysis lens and afforded researchers and participants the opportunity to co-construct the knowledge gained from the data corpus. Findings focused on the ways participants interacted with the study unit, how they found agency as writers, took pride in their writing, and ownership of the narratives of their communities.