The present work refers to one of the central subjects of the Legal Theory: the concept of sanction. Many of the basic legal concepts - and the concept of Law itself - are strictly connected with it, in such a way that a careful study on this subject will make possible that many other basic questions of the Law are, if not solved, at least clarified. Because of the innumerable subdivisions caused by that the complexity of the subject, it had become necessary to delimitate the studied object. Therefore, within the wide area of interest presented by the subject, the researcher has opted to focus his/her work on more modest objectives: to recognize and to present the main problems concerning the concept of sanction inside the work of three specific authors - Jeremy Bentham, John Austin and Hans Kelsen -, being them all part of the same legal thought tradition, the analytical school of jurisprudence. Such choice is justified by the unquestionable importance that the authors confer to the sanctions in their legal theories.