Because of increasing calls for school accountability, an increased emphasis placed on the role of the teacher, and theoretical connections between teacher beliefs and classroom action, a critical need exists to examine teacher professional development programs to determine their impact on teacher belief systems, teaching practices, and student learning. The primary goal of this study was to assess elementary teachers' science teaching efficacy as they participated in a large-scale professional development program and to determine the relationship of these beliefs with student learning. It was found that elementary teachers who participated in a long-term, intense (over 100 contact hours annually) science professional development program displayed significant gains in their science teaching self-efficacy. Several background variables were found to be predictive of teacher beliefs including how often teachers spend teaching science. Males tended to display more positive beliefs than their female counterparts. Although a small portion of the variance was explained, teacher beliefs and the number of hours participating in the research-based professional development program were significantly predictive of students' science achievement. Other factors may be involved in teachers' beliefs and their connection with student learning, including classroom practices, curriculum materials, support systems, and student background variables. These factors should be the target of future investigations. (Contains 5 tables.)