Gaming has played an important part in our daily lives for quite some time now. As a result, many researchers are interested in the various ways in which gaming has an impact beyond its own context. This dissertation explores one particular type of impact, i.e., the impact of gaming on organizations. It theorizes that gaming is a frame of mind that influences what we find important when it comes to communication and collaboration with our colleagues at work. To explore this further, this dissertation first develops the notion of ‘playful organization’. Using a framework of organizational culture and structure, the dissertation tries to find playful organizations where online gamers play and work. It re-evaluates previous empirical studies of online gaming communities and professional organizations. It also looks into the ‘corporations’ of the massively multiplayer online game EVE Online, based on an ethnographic study. Finally, it looks into the communities and work organizations of a panel of Dutch online gamers, listening to the panelists’ ideas about the extent of playful organization in both contexts and subsequent comparisons between the two. This dissertation is thus an interdisciplinary and in-depth organizational study of online gamers’ communities and work organizations, in an attempt to gain insights into gaming’s impact on organizations.