This collaborative action research study examined the development of critical thinking when the See, Think, Wonder thinking routine was implemented in a preschool classroom. One preschool teacher undertook this research with 13 preschoolers (aged 3-4 years). The thinking routine was conducted as an in-depth group discussion during circle time. The data collection for the research included field notes, vignettes and document analysis. The results indicated that the routine promoted critical thinking skills in preschool aged children. These included the ability to analyze information presented to them and the curiosity to want to learn more. The routine also provided instructional aids and assisted in making children’s thinking visible. The See, Think, Wonder thinking routine can be a potential pedagogical tool for the promotion of critical thinking in young children. Opportunities for such routines can be created as part of the structured curriculum or during self-chosen activities in the preschool.