While Web 2.0 tools are increasingly being adopted by academic libraries to connect with patrons, they are not actively used to facilitate knowledge management (KM). This study investigates the awareness and comfort of librarians, their perceived usefulness of KM using Web 2.0, organizational readiness, and the ways in which these affect the library adoption of KM using Web 2.0. The survey questionnaire was completed by 101 librarians from 35 countries in 6 continents. Most respondents had heard of KM, were comfortable with Web 2.0, perceived KM using Web 2.0 to be highly useful, but were not entirely sure if their libraries were ready to adopt KM. Comfort with Web 2.0 was found to impact perceived usefulness, which in turn, strongly affected the likelihood of adoption of KM using Web 2.0. This is the first study that combines KM using Web 2.0 from the perspective of academic librarians globally, and has important implications for theory and practice.