During the last decade, there has been a growing interest for theorizing in the information systems (IS) discipline. One important impetus for this was the call for theo-rizing the IT artefact as articulated by Orlikowski & Iacono (2001). Another impetus was similar claims by Benbasat & Zmud (2003). Besides concrete theory contributions, there have been further discourses on what to theorize and how to theorize. It is not only the IT artefact that needs theorizing, following claims by Orlikowski & Iacono (2001). There are also claims for theorizing practices (e.g. Feldman & Orlikowski, 2011). There is also a growing interest for the constituents of a theory and how to theorize (e.g. Gregor, 2006). This is actually well represented in pragmatic research approaches, such as design research (e.g. Gregor & Jones, 2007; Kuechler & Vaishanvi, 2012) and action research (Davison et al, 2012). Following these interests in theorizing IT artefacts and practices we are happy to present this special issue.