The article concerns the limitations of the freedom of shaping the legal relationship by the parties on the grounds of private international law binding in Poland. It is devoted to the specific issue of limitations of the effects of the choice of law on the grounds of the protection of third parties. The rules related to this issue have been included both in the sources of European law (“Rome I” and “Rome II” regulations, as well as in the Polish law – Private International Law of 2011). They concern the choice of law for contractual and non-contractual obligations, for a power of attorney and for matrimonial property regimes. The purpose of these rules is to protect the knowledge of a third party or the rights acquired by them. The article considers various possibilities to exclude the effectiveness of a law chosen for the protection of a third party, while respecting the wills of the parties to the legal relationship as much as possible.