This study was conducted to investigate eighth-grade science teachers' self-efficacy during the implementation of a new, problem-based science curriculum. The curriculum included applications of LEGO® robotics, a new technology for these teachers. Teachers' responded to structured journaling activities designed to collect information about their self-efficacy for teaching with the curriculum and, later, to a survey designed to probe their self-efficacy for enacting specific elements of the curriculum. Participants reported high confidence levels throughout the study but expressed some concerns related to their local contexts.