Knowledge Management (KM) emerged as a significant topic of management interest in the mid-1990s. By the early 2000s, KM practices were widespread across organizations and have become a topic of widespread interest to researchers in several disciplines. However, this widespread interest and adoption also raised significant concerns. Researchers identified many failures in KM implementation and some argued that KM was simply the latest in a series of management fads. KM is a management innovation -a concept offering opportunities to improve organizational performance and competitive position. Innovation adoption is often as a rational phenomenon, following patterns identified by Rogers (2003). However, an alternate view on innovation is proposed by Abrahamson (1991), who suggests that such decisions are often not rational but rather driven by managers' need to be seen to be innovative, following management fads and fashions. This paper examines whether KM is a management fad or fashion. It uses the two-stage framework proposed by Abrahamson (1991) to examine the discourse and the diffusion of specific innovations. An extensive bibliographic review was carried out over a 20-year period, from 1990-2009, to determine patterns in the discourse. Next, using a set of seven Themes developed from this review, the actual patterns of diffusion of KM in five professional services firms were examined. While the bibliometric analysis demonstrated that KM has sustained a high level of interest over the last 10 years and is not seen to present the typical characteristics of a management fad, actual practice in the field differs from what is recommended within the literature.