Social presence is a theory derived from social psychology to explain social interactions in a mediated communication and is defined as the degree to which interlocutors in a communications medium perceive each other as real. This study investigates the effect of computer-mediated communication on the social presence of international students who spoke English as a foreign language in two Web-based graduate courses offered in the United States and aims to explore how linguistic and cultural differences influenced their social presence. (Contains 4 tables.)