Text of the provision
Art. 166. Legitimacy of a child may be impugned only on the following grounds:
(1) That it was physically impossible for the husband to have sexual intercourse with his wife within the first 120 days of the 300 days which immediately preceded the birth of the child because of: (a) the physical incapacity of the husband to have sexual intercourse with his wife; (b) the fact that the husband and wife were living separately in such a way that sexual intercourse was not possible; or (c) serious illness of the husband, which absolutely prevented sexual intercourse;
(2) That it is proved that for biological or other scientific reasons, the child could not have been that of the husband, except in the instance provided in the second paragraph of Article 164; or
(3) That in case of children conceived through artificial insemination, the written authorization or ratification of either parent was obtained through mistake, fraud, violence, intimidation, or undue influence.
(255a)
Family Code of the Philippines, Executive Order No. 209, approved July 6, 1987. The Code took effect on August 3, 1988 (Republic v. Orbecido III, G.R. No. 154380, October 5, 2005). Reproduced in full.
What this article means
The presumption of legitimacy is strong, and this article makes it hard to overturn: legitimacy may be impugned only on the listed grounds — nothing else counts.
- Physical impossibility of access during the first 120 of the 300 days before birth — because the husband was physically incapable, the spouses were living apart so intercourse was impossible, or the husband had a serious illness that absolutely prevented it.
- Biological or scientific proof (such as DNA or blood-type evidence) that the child could not be the husband's — except in the authorized artificial-insemination case of Article 164.
- For artificial insemination, that the required written consent was vitiated by mistake, fraud, violence, intimidation or undue influence.
Note what is not a ground: the mother's own statement against the child (see Article 167) can never defeat legitimacy.
Questions about this provision
- Can a mother's own statement or admission make her child illegitimate?
- On what specific grounds can a husband legally dispute that a child born during the marriage is his?
Related provisions
- Article 167 — the mother's declaration cannot bastardize the child.
- Article 170 — the deadlines for an action to impugn.
Cases citing this article
- Bernie Santiago vs. Rommel C. Jornacion and The City Civil Registrar of Marikina City, G.R. No. 230049, October 6, 2021 — read the decision on LawPhil →
- Lowella Yap vs. Almeda Yap, Hearty Yap-Dybongco and Diosdado Yap, Jr, G.R. No. 222259, October 17, 2022 — read the decision on LawPhil →
- Richelle Busque Ordoña vs. The Local Civil Registrar of Pasig City and Allan D, G.R. No. 215370, November 9, 2021 — read the decision on LawPhil →
- Eugenio San Juan Geronimo vs Karen Santos, G.R. No. 197099, September 28, 2015 — read the decision on LawPhil →
- People of the Philippines vs. Joel Abat y Cometa, G.R. No. 202704, April 2, 2014 — read the decision on LawPhil →
Compiled automatically from Supreme Court decisions published on LawPhil that expressly cite this article, most frequently cited first. A listing means the decision cites the provision — it is not a statement that the case is the leading authority, and it does not show whether a ruling has since been modified or abandoned. Always read the decision itself.