Despite the longstanding nature of social network theory and its application to research on communication technologies, few IS studies employ social network analysis (SNA) concepts; the few that do are by organizational communication scholars. A recent stream of work by IS scholars is to apply SNA to study research collaboration – although this has mostly focused on individual IS conferences. We analyze frequent coauthors in five IS journals from 1999-2007 to show that most of these frequent coauthors primarily publish with their PhD students (what I label “supervisory coauthorship”). Two-thirds of frequent coauthors with 7 or more distinct partners mostly publish with their former PhD students, while less than one-third mostly publish with peer scholars. Nearly 85% of frequent coauthors were affiliated with North American institutions; two or more were located in the UK, Singapore and Hong Kong. We offer insights about the high rate of coauthorship in IS journals.