In this era of evolving health care systems throughout the world, technology remains the substance of health care. Medical informatics comprises a growing contribution to the technologies used in the delivery and management of health care. Diverse, evolving technologies include artificial neural networks, computer-assisted surgery, computer-based patient records, hospital information systems, and more. Decision-makers increasingly demand well-founded information to determine whether or how to develop these technologies, allow them on the market, acquire them, use them, pay for their use, and more. The development and wider use of health technology assessment (HTA) reflects this demand. While HTA offers systematic, well-founded approaches for determining the value of medical informatics technologies, HTA must continue to adapt and refine its methods in response to these evolving technologies. This paper provides a basic overview of HTA principles and methods.