In this chapter, I analyze computer-mediated communication in the form of online, synchronous, professional discourse in the multimodal video conference environment with the aim of assessing social co-presence (Kang et al., 2008). I argue for the applicability of discourse analysis methodology by presenting extracts of video conference communication which illustrate how talk-in-interaction contributes to or threatens the three elements of social co-presence: co-presence, social richness of the medium, and interactant satisfaction. Examples of interaction illustrate how disruptions in mediation serve to threaten co-presence by isolating interlocutors, how multiple modes of communication are exploited to ground participants in a shared communicative environment thereby establishing social connectedness, and how multimodal communication allows for iconic or paralinguistic support of the discursive expression of emotional stance. The chapter concludes with feature recommendations for video conference software development from the perspective of social co-presense.