Filiation is the legal bond that connects a person to their parents. It determines essential rights — surname, child support, inheritance, identity — and is regulated in articles 558 to 593 of the Civil and Commercial Code of Argentina. Adoption, in turn, is one of the most sensitive institutions of family law: it creates a parental bond where none previously existed, with profound consequences for the adoptee, the adoptive parents, and in certain cases the biological family.
Argentine filiation law combines established principles — biological truth, equality between children born within and outside marriage — with modern developments such as filiation derived from assisted human reproduction techniques (ART), where procreational intent displaces the genetic bond as the primary criterion. We accompany each case with the technical complexity and human sensitivity it requires.
When a child's father has not been legally recognised — either because the father never voluntarily acknowledged the child or because there is a dispute over who the biological parent is — this proceeding can be initiated so that the court declares and establishes paternity. A DNA test is the central evidence, though not the only one. Once filiation is established, the child acquires all rights: surname, child support, inheritance, and legal bond with the paternal family. The action may be brought by the child (at any age) or their legal representative if a minor (arts. 582 to 587 of the Civil and Commercial Code).
In most cases maternity is established automatically at birth. However, there are situations where that determination is not automatic or is in dispute — for example, when there is no birth record, when there is confusion about the mother's identity, or in certain cases related to ART. Through this proceeding, the court formally establishes who the child's legal mother is, with all legal effects.
If a person is listed as the father on the birth certificate but there are well-founded doubts about their biological paternity — or it is known that they are not the father — the law allows that filiation to be challenged. It may also occur that the man himself wishes to legally dissolve the bond with a child he acknowledged by mistake or under duress. The court will order a DNA test, and if the absence of a biological link is confirmed, the birth certificate will be amended. This action has specific time limits and standing requirements: arts. 588 to 593 of the Civil and Commercial Code.
Although less common, there are cases where the registered maternity does not match the biological reality — due to identity substitution, registration error or other circumstances. Through this proceeding, the court is asked to annul the maternal filiation and, where applicable, determine who the real mother is. Biological evidence is the central element.
Assisted reproduction techniques — in vitro fertilisation, egg or sperm donation, surrogacy — raise situations that traditional law does not resolve automatically. The Civil and Commercial Code (arts. 560 to 564) establishes that filiation in these cases is determined by prior, informed and free consent given before the physician or notary, not by the biological bond. When that consent was not properly recorded, there is conflict between the parties, or the actual family situation does not match what was registered, recourse to the courts is necessary.
When a father or mother wishes to voluntarily acknowledge their child — without the need for a court proceeding — they may do so by means of a formal declaration before the Civil Registry, a notary, or in court (arts. 571 to 575 of the Civil and Commercial Code). This is the simplest and most direct way to establish filiation. Once completed, it produces all its legal effects immediately: surname, child support, inheritance, and bond with the acknowledging party's family.
Adoption is the process for legally incorporating a child into a family. The court evaluates the best interests of the child and the suitability of the prospective adoptive parents. The Civil and Commercial Code (arts. 594 to 637) provides for three forms: full adoption (extinguishes the bond with the biological family and creates a new one identical to the filial bond), simple adoption (maintains the bond with the biological family except with respect to parental responsibility), and integration adoption (when the child of a spouse or partner is adopted).
An action to set aside an adoption granted with legal defects — fraud, concealment of information, or irregular consent. This is an exceptional proceeding: courts apply very strict criteria because it involves undoing an already established family bond.
Every adoptee has the right to know their biological identity (art. 596 of the Civil and Commercial Code; Convention on the Rights of the Child, arts. 7 and 8). If access to that information was denied or is unavailable, the court may order its disclosure. Knowing one's biological origin does not affect or modify the adoptive bond.