This research employs a social network analysis (SNA) approach to study the longitudinal changes in co-authorship and affiliations of authors, who published in the Australasian Conference on Information Systems (ACIS) from 2001 to 2011. The research explores the structural patterns of co-authorship at the institution and individual author levels, and found research collaboration tend to occur between authors in the same regions and institutions. Descriptive findings further revealed key authors with rich and diverse co-authorship ties, as well as the tendency of authors to collaborate in silos within institutions. A longitudinal SNA method was performed to statistically deduce the changing patterns of co-authorship and affiliations from a sample of the authors in this 11-year period, which complements the descriptive findings. The discussion of our findings results in recommendations to improve the ACIS community’s productivity and in directions for future studies concerning the applications of SNA in examining research collaboration.