This thesis deals with the institution of adoption in Croatian family law, with a special emphasis on the legal framework and practice in the context of the best interests of the child. Adoption, as a permanent legal relationship, enables children without adequate parental care to create a family and ensures their protection and emotional and social stability. The paper analyzes the legal prerequisites for adoption, including the conditions on the part of the child and potential adoptive parents, as well as the procedure for establishing an adoption, which includes collecting the consent of all parties involved. The importance of the Family Act and international documents regulating this institution is emphasized. A special part of the paper is dedicated to the analysis of the judgments of the European Court of Human Rights against Croatia, which indicate shortcomings in the implementation of the law and procedural shortcomings, such as the exclusion of biological parents from key stages of the adoption procedure. The judgments in the cases of X. v. Croatia and A.K. and L. v. Croatia illustrate violations of Article 8 of the Convention for the Protection of Human Rights and Fundamental Freedoms, which guarantees the right to respect for private and family life. The paper emphasizes the need to strengthen transparency and ensure the procedural rights of all parties involved in adoption. Despite the existing legislative framework, challenges remain in balancing the best interests of the child with the rights of adoptive parents and biological parents. Adoption has lasting legal and emotional effects, so it is crucial that national authorities act responsibly and professionally. Further harmonization of laws with international standards and training of professionals are recommended in order to ensure better protection of children's rights.