The book summarizes the author's personal experience in the field of clinical surgery, management of medical facilities and medical services, in the development of medical information systems for various purposes, including advisory expert diagnostic systems and the choice of optimal solutions in difficult situations, in managing the quality of medical care, and also teaching informatics in the system of medical postgraduate education.An attempt was made to present in an accessible meaningful form the ways and methods of information support for these various aspects of the practice of doctors, regardless of their narrow specialization. The material is presented in free language. The book is supplied with various applications.The manual is intended for readers with a higher medical education, clinicians, social hygienists, health care organizers. It can also be useful for developers of medical information systems who have only a mathematical or technical education.