Around the world, tremendous sums of money and time are being spent modernizing the health care ecosystem to improve outcomes and reduce cost. One of the critical hypotheses behind many of these efforts is that the collection of electronic data, such as longitudinal electronic health records (EHRs), will enable tools that provide actionable insights about a patient’s condition required to make more intelligent medical decisions. This datadriven vision promises to improve care in facilities ranging from emergency rooms to general practitioner offices.However, these goals are hampered by many fundamental challenges: overwhelming amounts of data, siloed information repositories with non-standard semi-structured and multi-modal data streams, time-limited practitioners with great domain knowledge but often little statistical training, and large semantic gaps between the raw data that is collected and the information needs of people who are delivering care or conducting effectiveness studies. Solutions to these challenges will require multi-disciplinary visual analytics solutions that combine efforts across the several intersecting research communities: data mining, visualization and visual analytics, medicine, and medical informatics. The Workshop on Visual Analytics in Health Care was held to help build the community of scientists required to address these challenges. The one day workshop took place on October 24, 2010 and was organized as part of IEEE VisWeek in Salt Lake City, Utah, USA. The program included keynote speakers, technical presentations of novel research, and a student poster session that allowed for informal discussions between workshop attendees.