BACKGROUND Public health professionals engage in frequent exchange of health information while pursuing the objectives of protecting and improving population health. Yet, there has been little study of the information work of public health workers with regard to information exchange. Our objective was to gain a better understanding of information work at a local health jurisdiction before and during the early stages of participation in a regional Health Information Exchange. METHODS We investigated the information work of public health workers engaged in disease surveillance activities at a medium-sized local health jurisdiction by conducting semi-structured interviews and thematically analyzing interview transcripts. RESULTS ANALYSIS OF THE INFORMATION WORK OF PUBLIC HEALTH WORKERS REVEALED BARRIERS IN THE FOLLOWING AREAS: information system usability; data timeliness, accuracy and completeness; and social interaction with clients. We illustrate these barriers by focusing on the work of epidemiologists. CONCLUSIONS Characterizing information work and barriers to information exchange for public health workers should be part of early system design efforts. A comprehensive understanding of the information practice of public health workers will inform the design of systems that better support public health work.