Health information systems have the potential to improve patient safety and quality of care. During last decades many health information systems have emerged. Despite their widely reported advantages, not all these systems have been accepted by users or adopted in health care organizations. Usability problems are among the main barriers which impose heavy cognitive and physical demands on users and may result in unsuccessful user-system interaction. This book reviews the design aspects of an information system that may impact user interaction. It also employs and compares different usability evaluation methods from the filed of Human Computer Interaction to evaluate usability of computerized systems in healthcare domain. Moreover, a new framework for reporting usability problems is introduced. The content of this book should help shed some light on potential usability issues of health information systems, and should be especially useful to professionals in Medical Informatics and Health Information Management fields, or anyone else who may be considering development, implementation or purchasing of health information systems.