Using collaborative action research, this study aimed to explore the practice of implementing a science integrated curriculum in a kindergarten classroom in Taiwan. The author served as a curriculum consultant, and two kindergarten teachers served as co-teachers. The participants were 30 young children. Data sources included classroom observations, interviews, and other documentation. The findings were as follows. (1) The science thematic curriculum was developed from the young children’s interest in bats. The kindergarten teachers applied the science thematic approach to integrate science and other content areas in the thematic curriculum focused on the science theme “Bats.” (2) The young children learned about the science concepts of bats’ characteristics, habits, and habitats, as well as the cultural meaning of bats in the local culture. (3) The kindergarten teachers had to solve problems in science teaching, such as problems related to the children’s observation of bats and teachers’ content knowledge in science teaching. This study provides us a lens to examine how early childhood teachers implemented a science thematic curriculum in a kindergarten classroom. Recommendations for science teaching in early childhood education are also discussed in the paper.