Overriding mandatory provisions are mandatory provisions that are applicable in situations with an international element. The author analyses overriding mandatory norms in the European private international law and in the Croatian national private international law. The definition of such norms provided in the 2017 Croatian Private International Law Act is almost a verbatim copy of the definition provided in the Rome I Regulation on the law applicable to contractual obligations. The 1982 Croatian Private International Law Act did not provide for a definition of overriding mandatory norms but it was uniformly accepted in the scholarly interpretations that those types of mandatory norms were accepted by the Croatian private international law system. Moreover, the 1982 PIL Act included a substantive family law provision, which was, in essence, an overriding mandatory provision. However, Croatian courts and practitioners have been reluctant to refer explicitly to an applied norm as an overriding mandatory one. The reasons behind that might be that that the courts were better acquainted with the public policy exception, since public policy was explicitly mentioned in the 1982 PIL Act, as well as in some other legal acts. In addition, the legislator does not explicitly note that a provision is an overriding mandatory one in the provision itself, which leads to the outcome that the courts and other practitioners are burdened with a complex task of interpretation of a provision they think might be an overriding mandatory one. The author aims at providing guidelines to facilitate that task.