Universities with a strong global presence host a large number of international doctoral students. Many of these students teach undergraduate courses as part of a teaching assistantship. There are many benefits associated with international teaching assistants. These include cultural exchanges within the universities and enhanced preparation for students entering into careers that are increasingly international in scope. These international teaching assistants, however, often encounter unique challenges. An understanding of these challenges is imperative in order to better meet their needs, as well as those of the undergraduate students in their classes. This qualitative study examined the experiences of international teaching assistants from science and math education departments in a Midwestern US university and their students' views about learning from them. Data sources included video and audio-taped semi-structured interviews conducted with seven international teaching assistants and their students. The findings revealed the teaching assistants experienced different kinds of language and cultural and contextual challenges. Accent and fluency in speaking, correct pronunciation of the words, and the differences in science and mathematics jargon across different countries are examples of linguistic challenges. The difficulty in understanding US humor, customs, values, and beliefs are examples of cultural challenges. In response to these challenges, the teaching assistants developed coping strategies such as honesty and being open to students. The findings revealed students experienced some difficulties such as language issues, but they also had positive experiences such as learning about different cultures.