OBJECTIVE To reflect about medical informatics as a discipline. To suggest significant future research directions with the purpose of stimulating further discussion. METHODS Exploring and discussing important developments in medical informatics from the past and in the present by way of examples. Reflecting on the role of IMIA, the International Medical Informatics Association, in influencing the discipline. RESULTS Medical informatics as a discipline is still young. Today, as a cross-sectional discipline, it forms one of the bases for medicine and health care. As a consequence considerable responsibility rests on medical informatics for improving the health of people, through its contributions to high-quality, efficient health care and to innovative research in biomedicine and related health and computer sciences. Current major research fields can be grouped according to the organization, application, and evaluation of health information systems, to medical knowledge representation, and to the underlying signal and data analyses and interpretations. Yet, given the fluid nature of many of the driving forces behind progress in information processing methods and their technologies, progress in medicine and health care, and the rapidly changing needs, requirements and expectations of human societies, we can expect many changes in future medical informatics research. Future research fields might range from seamless interactivity with automated data capture and storage, via informatics diagnostics and therapeutics, to living labs with data analysis methodology, involving sensor-enhanced ambient environments. The role of IMIA, the International Medical Informatics Association, for building a cooperative, strongly connected, and research-driven medical informatics community worldwide can hardly be underestimated. CONCLUSIONS Health care continuously changes as the underlying science and practice of health are in continuous transformation. Medical informatics as a discipline is strongly affected by these changes and is in a position to be a key, active contributor in these changes.