The purpose of this evaluation was to measure the impact of the Baylor College of Medicine (BCM) Summer Institute on science performance of students whose teachers participated during the summers of 2011 and 2012. Paired t-tests revealed statistically significant increases in a sample of elementary students' Stanford 10 science scores at 3rd through 5th grades in 2012 and at 5th grade in 2013. For the middle-school student sample, significant increases were found at 7th and 8th grades in 2012 and 2013. Linear mixed-effects modeling revealed elementary students' previous year Stanford 10 science scores and teachers' additional hours of professional development were the strongest predictors of students' post BCM teacher participation science performance in both years. Propensity score matching yielded increases in elementary and secondary students' (State of Texas Assessments of Academic Readiness) STAAR scores following teacher participation relative to comparison group students; however, the differences were not statistically significant at p < 0.05. The level of mentoring and peer support that teachers received during the school year was not measured in this evaluation and could have accounted for differences in science performance outcomes at elementary and secondary levels.