This descriptive-correlational study sought to investigate teachers' levels of Personal Science Teaching Efficacy (PSTE) and Science Teaching Outcome Expectancy (STOE) using the Science Teaching Efficacy Beliefs Instrument (STEBI). The population included all teachers completing a CASE Institute training session during summer 2010. Assessments were made at two points. First, the participants were assessed by using a post-then-pre assessment with a second follow-up assessment after nine months of implementing the new curriculum. Demographic characteristics are presented to provide insight into the participants. The teachers experienced gains during the institute on both their personal science teaching efficacy and their science teaching outcome expectancy. However, after nine months of using the curriculum, their efficacy remained high while their outcome expectancy returned to the same levels held before attending the professional development. It appears the CASE Institute had a lasting impact on the participants' personal efficacy, but not their outcome expectancy beliefs. Recommendations are made for future research.