While traditional MIS theory focuses on planned decision making as the main managerial activity, in this paper, we submit that improvisation is a frequent and ubiquitous process in economic institutions, such as markets and hierarchies. We argue further that improvisation is a much more grounded individual and organizational process than planned decision making. As a consequence, if information technology is used to automate structured, planned decisions, the risk is to automate ungrounded organizational processes. This may be an explanation of why many automated routines make little sense, or at best embed the knowledge of a novice, and subsequently have to be continually “worked at” by members in order to keep them viable. Finally, we suggest ways of harnessing information technology to support improvisation.