In the summer of 1991, the authors conducted a systematic user-based study of electronic mail at the World Bank headquarters in Washington, D.C. The World Bank is a leader among UN organizations in using innovative communication media. The focus of the research was to understand the technical and organizational issues associated with the implementation and use of new information technologies in an international organization. This article presents the results and recommendations based on the field study. Quantitative and qualitative data were collected from members of four large-scale units to generate an accurate and robust picture of the use and impact of electronic mail. Two of the units were primarily responsible for outward-facing functions (e.g., advising member countries on investment and development), and two performed inward-facing functions that support the Bank. Each unit contained a representative proportion of support- and professional-level staff. Organizational mission and job role were expected to influence the needs and usage styles of employees with respect to information technology. A highly structured standardized survey gathered information about the nature and volume of electronic communication, emerging methods for managing electronic messages, and the advantages and disadvantages of the medium within the context of day-to-day task responsibilities. In-depth qualitative data were collected from focus groups of participants from the sampled units. The qualitative data provided interpretive and illustrative information not readily obtained from questionnaires. Analyses showed that electronic mail has become a widely used and popular communication medium at the World Bank. However, a number of technical and organizational constraints currently inhibit the potential of electronic mail to serve as a generic infrastructure to support the diverse needs of knowledge workers.