This study explores the experiences of six urban middle school students in an authentic science inquiry program. Drawing on data including teaching journal entries, student work folders, and semistructured focus group interviews of six participants, the findings explore six dimensions of authentic science inquiry, an approach to science inquiry in which: (a) students develop authentic and personally relevant science knowledge; (b) students' funds of knowledge shape their inquiries; (c) students' relationships with science and sustained interest in science are transformed; (d) students' identities as potential scientists are affirmed; (e) students engage in science as a social enterprise; and (f) students develop a sense of agency. The findings situate authentic science inquiry as an individual and collective characteristic of learners and the learning community. We make the case that authentic science inquiry projects provide students with a greater sense of academic agency, afford students opportunities to gain expertise, and have the potential to challenge students' understandings of science, enhance how they see themselves in relationship to science, and improve their achievement in science. The first author worked as a science staff developer in a large urban school district. In collaboration with a local science organization, the school district began planning for a districtwide science exposition. We embraced the rhetoric of "Science for All" and wanted to move beyond the typical science fair model in which students who had interest and parental support completed science projects at home. Instead, every student would complete science inquiry projects in their science class, schools would hold school-wide science expositions, and each school would send four projects to the district-wide exposition. Instead of awarding first-, second-, or third-place prizes, the school and district science expositions would celebrate work that met or exceeded standards. As part of a grass-roots approach, several full-day professional development sessions were devoted to working with representative teachers from more than 50 schools in the district. Through experiential sessions and dialogue, we engaged with questions about what science inquiry is, how to engage students in inquiry-based learning in the classroom, and how to prepare students to present their inquiries formally, including display boards and oral presentations.Rather than presenting the teachers with an inquiry model to implement, we involved teachers in developing the model. At one of the meetings, we asked teachers to brainstorm criteria for the Correspondence to: María S. Rivera Maulucci;