Information technology increasingly figures into the activities of health-care workers, patients, and their informal caregivers. The growing intersection of anthropology and health informatics is reviewed, a field dedicated to the science of using data, information, and knowledge to improve human health and the delivery of health-care services. Health informatics as a discipline wrestles with complex issues of information collection, classification, and presentation to patients and working clinical personnel. Anthropologists are well-suited as collaborators in this work. Topics of collaborative work include the construction of health and illness, patient-focused research, the organization and delivery of health-care services, the design and implementation of electronic health records, and ethics, power, and surveillance. The application of technology to social roles, practices, and power relations that is inherent in health informatics provides a rich source of empirical data to advance anthropological theory and methods.