The overall purpose of this longitudinal study was to investigate the effectiveness of a science method course in training pre service teachers to teach science. This effectiveness was measured by examining changes in pre-service teachers' science teaching confidence level as reflected in their ability to implement different instructional strategies and determining their students' gain in science knowledge during the student teaching semester. This study tracked pre-service elementary science teachers from the time they took their science method course in the teacher education program, which focused on using inquiry strategies, to the completion of their student teaching. The data (n=41) were collected over four consecutive semesters through quantitative and qualitative measures. The population of this study was pre-service teachers enrolled in a science method course. The effectiveness of science teaching was determined by comparing pre and posttest results of the students taught by the pre-service teachers during their student teaching semester. Their science teaching confidence level was measured quantitatively by comparing pre and post Science Teaching Efficacy Beliefs Instrument (STEBI-B) scores and qualitatively by classroom observation; lesson plans; survey questionnaire and structured open ended interviews during their student teaching semester. The quantitative and qualitative data were triangulated and analyzed by analytic induction and constant comparative method. It is evident from this study that the pre service teachers demonstrated confidence in implementing both traditional and the inquiry method in the classroom instruction.