In this study the author presents his own conception of social security criminal law, emphasising the fact that this term is not only non-normative, but it is also not used in the literature pertaining to the criminal and to the social security laws. Starting from the assumption that Polish legislator provides for criminal responsibility for breaching obligations imposed on social security entities, we have to acknowledge, though, that indeed it is possible to distinguish a group of criminal regulations which may be covered with the term social security criminal law. This distinguished group includes: offences classified in Art.98 para.1 and 3 of the Act on social security system, the crimes classified in Art.215-221 of the Act on organisation and functioning of pension funds, and moreover two crimes from the Criminal Code specified in Art.218 §1a and in Art.219. Their common features are: 1) the character of legal interest which they protect – proper functioning of the social security system, and 2) the subject of prohibited act, who, in fact, may be exclusively a participant of this system. The social security criminal law is a part of business criminal law, but functionally it is related to social security law, whose regulations allow for correct designation of criminalisation boundaries, particularly that a provision of several prohibited acts is a blanket provision. Distinction of the social security criminal law allows for better interpretation of the regulations classifying crimes and offences, protecting the proper functioning of social security system, which has significant importance for the practice and improves the estimation of legislative needs in this scope.