In 16 Flying Start early childhood education and care (ECEC) settings within a Local Authority in Wales, observations of adult-child interactions, using the Sustained Shared Thinking and Emotional Wellbeing Scale (SSTEW), highlighted that interactions that support children's problem solving, curiosity, concept development, and higher-order thinking were the least well developed aspects of practice. A two-day professional learning intervention 'Talking Science', underpinned by a socio-cultural understanding of science learning in ECEC was designed. The intervention was delivered via a collaborative, socio constructive model of delivery en masse to all 64 practitioners in the 16 Flying Start settings. This qualitative mixed method research project adopted an interpretivist paradigm; the aim was to better understand ECEC practitioners' perceptions of science and how these perceptions both shaped provision and supported children's concept development in their settings. Data collection took the form of scribed notes from group discussions, feedback from practitioners during discussions and evaluation feedback about 'Talking Science'. The experiential professional learning programme with a focus on science in everyday practice appeared to be supportive of practitioners' developing confidence and subsequent engagement with science provision for young children. 'Talking Science' also provides a model which may have wider implications when designing ECEC professional learning.