OBJECTIVE This article reviews key communication issues involved in the design of effective and humane eHealth applications to help guide strategic development and implementation of health information technologies. BACKGROUND There is a communication revolution brewing in the delivery of health care and the promotion of health fueled by the growth of powerful new health information technologies. CONCLUSIONS The development, adoption, and implementation of a broad range of new eHealth applications (such as online health information websites, interactive electronic health records, health decision support programs, tailored health education programs, health care system portals, mobile health communication programs, and advanced telehealth applications) holds tremendous promise to increase consumer and provider access to relevant health information, enhance the quality of care, reduce health care errors, increase collaboration, and encourage the adoption of healthy behaviors. CONCLUSIONS With the growth of new and exciting health information technology opportunities, however, comes the daunting responsibility to design interoperable, easy to use, engaging, and accessible eHealth applications that communicate the right information needed to guide health care and health promotion for diverse audiences.