This research examined the critical incidents of 10 United States (US) early childhood student teachers during a three-week university-sponsored international field experience conducted in three urban preschools in Kathmandu, Nepal. The purpose of employing the critical incident technique was to allow the US student teachers to reflect critically on successful and unsuccessful intercultural interactions in an effort to identify cultural assumptions about teaching young children. The approach was used not only to make assumptions visible, but also to make conceptual and behavioral changes based on what was learned from the critical reflection. The student teachers wrote weekly critical incidents, which were then discussed during weekly individual interviews. Three group discussions, a research journal, and field notes were used to triangulate the findings. A qualitative thematic analysis revealed five types of written critical incidents: descriptive, hypothetical, resistive, reflective, and integrative. Illustrative critical incidents are presented to compare and contrast how the international field experience allowed for productive reflection of cultural assumptions for some student teachers while leading to resistance to cultural assumptions for other student teachers. The findings suggest that outcomes vary based on the student teachers' ability not only to identify their cultural assumptions, but also to challenge their cultural assumptions with actions grounded in ethnorelative reflection when teaching diverse groups of young children in the US and abroad.