This study was designed to establish the efficacy of Teaching SMART (Teaching Science, Mathematics and Relevant Technologies); a science professional development program for teachers with students in grades 3 through 5. Teaching SMART promotes scientific inquiry and emphasizes the importance of equity, empowerment, exploration, and fun in the classroom. The paper focuses on two primary outcomes for the teachers and students who participated in the three year implementation of Teaching SMART: (1) the impact on science teaching practices of teachers and (2) effects on student achievement in science. This is an analysis of the first cohort of third grade students participating in three years of implementation with 129 initial teachers. In all, there are 964 third grade students from ten treatment and ten control schools. The authors are encouraged by the teachers reported change in practice and the concurrent student reports. The lack of significant effects on measures of student achievement may be due to a variety of factors including contextual pressures emphasizing reading and mathematics achievement. Repeated measures analyses of the recent FCAT scores at the student level may provide greater power. During the implementation of the Teaching SMART program there are a number of issues that may have influenced teacher practices and student achievement. Issues include the district context, and the Teaching SMART program structure and implementation. The school district's support was initially very strong, but waned as the program progressed. The supervisor for elementary science was routinely present for the opening of each of the multiple beginning training sessions and on half of those trainings her supervisor spoke of the district's support for the program. Delivery of the professional development by the resource teachers was always well planned and structured based upon the experience of the Teaching SMART program director. The authors found the implementation among repeated trainings was uniform, but that problems the resource teachers had were not always adequately addressed. Initially the resource teachers tended to deliver the training in didactic manner undermining the inquiry base of the program. Overall these context and programmatic issues may have slowed the growth of teachers participating in the program. This slowed growth for teachers combined with a lag in increases in student achievement scores offers some optimism for the success of the Teaching SMART program. (Contains 1 table and 3 figures.) [This paper was prepared for the annual meeting of the Society for Research on Educational Effectiveness Second Annual Conference held in Hyatt Regency, Crystal City, Virginia last March 1-3, 2009.]