Theories of how people learn and how science connects to students' lives provide frameworks for exploring the development of teachers' visions of effective science teaching. These frameworks can inform elementary teacher preparation programs about how to communicate theory-based practices of effective science instruction to support pre-service teachers' abilities to identify and enact science instruction that contributes to student learning. Part of a larger study, the present study uses a grounded theory design to examine three teachers' developing visions of effective science teaching through their teacher preparation and into their first year of teaching through a series of interviews. Findings revealed several factors contributing to their visions of science teaching: their memories of their experiences as elementary students, their teacher preparation, and institutional policies related to science instruction. Implications for helping novice teachers connect their visions with enacting practices situated in the realities of classrooms are discussed.