This study examines the interactions of educators and instructional designers during a four-week open online professional development course about using social media in education. Discourse analysis was used to elucidate points where national and organizational cultural differences arose, noting whether and how learners expressed and bridged differences. Findings suggest that the learners first identified with their national culture, and then, if they did not experience any cultural challenges, began to explore topics related to organizational culture. In this course, Chinese students were most likely to experience national cultural challenges, and Western participants were most likely to raise organizational culture issues. Language and national political climate also played a role in how and what learners expressed in an online learning environment. Flexible course design and facilitation can be used to help make learners from all cultural backgrounds feel more comfortable and engage in cross-cultural sharing.