The DIAdvisor is a large scale integrating project (IP) aiming at development of a prediction based tool which uses past and easily available information to optimise the therapy of type I and developed type II diabetes.The DIAdvisor does not depend on specific sensor technologies and technologies like standard strip sensing, minimally-invasive continuous glucose sensors and non-invasive methods.For safety reason, the DIAdvisor system will be able to self-assess the confidence of its proposed decisions. For safety reasons as well as for the sake of therapy improvements the system connects and provides information and trends to the Health Care Provider.Glucose prediction is difficult and requires advanced science. This can be achieved only by a well balanced group of eminent experts including academics, clinicians, user representatives and leading companies. This includes physiological modelling, identification theory, control theory, medical device technology, risk management theory, sensor science and user understanding.The expected impact of DIAdvisor will be improved diabetes control and quality of life in large populations of insulin treated patients, leading to fewer diabetic complications and lower Health Care costs. Moreover, the project will constitute a valuable opportunity for European companies to build up a special know-how leading products that profoundly and positively impacts the lives of millions with other indications than diabetes.