This study examined science teachers' conceptions of creativity in science education, pedagogical ideas, and contextual factors perceived as constraints on teaching for creativity and any differences in the conceptions of teachers from South Korea and the United States. Participants in the study consisted of 44 South Korean and 21 US secondary science teachers. Data was collected from open-ended and Likert-type questionnaires. Results indicated that each individual teacher's conception was considerably limited, but the teachers' conceptions of creativity as a whole group were consistent with the literature. In terms of teaching methods for creativity, the teachers commonly emphasized problem-based or project-based inquiry which was consistent with the literature. The South Korean teachers tended to consider ethics as a more important criterion for judging creativity than the US teachers and emphasized providing thinking opportunity for fostering creativity, while the US teachers emphasized environmental or emotional support. Possible sources of these differences were discussed. The commonly mentioned constraints included pressure of content coverage for high-stakes tests, difficulties in assessing creativity, and class size. Suggestions for professional development of teachers and further research questions were made based on the findings.