Portfolio management practices and theory continue to remain focused on a centralized “command and control” perspective. Even though many organizations promote and encourage self-organization, particularly within their software development teams, little is known about how or if IS project portfolios self-organize. Previous studies have explored self-organization at organizational, team, or project level, but do not explore self-organization at portfolio level. Self-organization facilitates the acceptance of innovative ideas and enables autonomous teams to respond to changes in requirements or in the environment without management intervention. This research-in-progress paper aims to firstly contribute to research by using the theory of complex adaptive systems to explain how one aspect of control, namely self-organization, can occur in portfolios of IS projects. Secondly, this study will, through the use of exploratory case studies, contribute to practice by determining the implications and challenges for managers of self-organizing IS portfolios.