This study empirically examines university students' perceptions and their views of when they adopt Instant Messaging (IM) and Short Messaging Service (SMS) and how they perceive and prefer these two media, in conjunction with other media (face-to-face, telephone, and email), in their university learning activities across two different cultural contexts: Australian university and Chinese university. The overall results of this study support some aspects of media richness theory. Although IM is perceived to be richer than email, it is not perceived to be the most popular medium for any situation. Data also demonstrate cultural differences in media perceptions of and preferences for new media. Specifically, Australian students have higher preference for email than their Chinese counterparts and Australian students also perceive SMS as leaner in terms of medium richness and have less preference for SMS than their Chinese counterparts. © 2007 IEEE.