New science curricula in Ontario position science, technology, society, and environment (STSE) objectives at the fore of all science courses. A professional learning community (PLC) consisting of 24 elementary teachers and a facilitation team was established to assist teachers in meeting the challenges of STSE education. Specifically, we examine (a) teachers' understandings of STSE as they engaged in the PLC and (b) the nature of the PLC that supported their efforts. Findings suggest that PLCs provide a supportive environment for exploring new ideas and practices. STSE was understood to have a range of orientations, and action was viewed as problematic. Theoretical apparatus, strong facilitation, collective capacity, and diverse membership were identified as key aspects of the PLC.