The purpose of this article is to summarize the 25 years of operation of the institution of the Ombudsman for Children in Poland. The Ombudsman for Children has constitutional status, and its powers are defined by law. Over the past 25 years, its powers have expanded, which has positively impacted its effectiveness. The Office of the Ombudsman for Children has also undergone a transformation. The article presents the most significant achievements in amending legal provisions for children and selected issues that ended in failure. The discussion concludes with de lege ferenda proposals for the constitutional and legislative authorities.