Informed consent as one of major problems of contemporary medical law and medical ethics is considered. Basic elements of this process are revealed. Standards determining patient's competence are described. The following issues are discussed: scope of information to be presented to patient; possible alternatives to particular treatment; risk degree, specifics and purpose of proposed treatment. Peculiarities of introducing principle of informed consent into pediatric practice are emphasized. Any child is most vulnerable patient therefore additional efforts are needed to protect his rights. Necessity to obtain child's approval to be examined and to be treated is issue of pressing importance.