Undergraduate college “science partners” provided content knowledge and a supportive atmosphere for K–5 teachers in a university–school professional development partnership program in science instruction. The Elementary Science Education Partners program, a Local Systemic Change initiative supported by the National Science Foundation, was composed of four major elements: 1) a cadre of mentor teachers trained to provide district-wide teacher professional development; 2) a recruitment and training effort to place college students in classrooms as science partners in semester-long partnerships with teachers; 3) a teacher empowerment effort termed “participatory reform”; and 4) an inquiry-based curriculum with a kit distribution and refurbishment center. The main goals of the program were to provide college science students with an intensive teaching experience and to enhance teachers' skills in inquiry-based science instruction. Here, we describe some of the program's successes and challenges, focusing primarily on the impact on the classroom teachers and their science partners. Qualitative analyses of data collected from participants indicate that 1) teachers expressed greater self-confidence about teaching science than before the program and they spent more class time on the subject; and 2) the college students modified deficit-model negative assumptions about the children's science learning abilities to express more mature, positive views.