The paper considers the issue of constitutional and conventional sources of one of the objectives in criminal proceedings, namely taking into account the legally protected interests of the victim (injured party). The author defines the notion of legally protected interests of the victim and distinguishes substantive-law and procedural interests. Both have constitutional and conventional sources as proven by the analysis of the European Court of Human Rights and the Polish Constitutional Tribunal case law. Effective protection of human rights and freedoms requires establishing provisions of substantive law, including criminal law, while their implementation should be guaranteed by introducing appropriate procedural mechanisms, in particular the victim’s right to court, including the right to a fair trial. The conclusion was therefore that the objective of criminal proceedings indicated in Article 2 § 1 para. 3 CPC is constitutionally and conventionally defined.