<p>Addressing research gaps in early childhood education and the Taiwanese context, this study examines preschool teachers’ pedagogical cognition and enactment in gender-responsive STEM education. Drawing on learning environments research, the study utilizes social cognitive theory (SCT) and gender schema theory (GST) to investigate how links between teacher self-efficacy, pedagogical beliefs, and practices manifest in shaping classroom environments. The study employed a multiple-case design involving 34 semi-structured interviews and 40 systematic observations of 14 female teachers. The findings reveal a persistent tension between enduring gendered beliefs and emerging reflective transformation. Although the participants implicitly associated STEM competence with boys, they actively promoted equity by using adaptive strategies, such as mixed-gender collaboration, equitable discourse, and implementing STEM challenge corners. However, low self-efficacy and institutional constraints, including parental expectations and vague curricular guidance, restricted the depth of enactment. This study contributes to learning environments research by demonstrating that achieving gender equity in early STEM education is a socially mediated process in which teacher agency plays a pivotal role in high-context sociocultural settings.</p>