Azcuna was born in Katipunan, Zamboanga del Norte on February 16, 1939. He received the degree of Bachelor of Arts, with academic honors, at the Ateneo de Manila in 1959 and the degree of Bachelor of Laws, cum laude, at the same institution in 1962. He was admitted to the Philippine Bar in 1963, placing 4th in the 1962 bar examinations. He forthwith embarked on a government career as Assistant Private Secretary of then Presiding Justice Jose P. Bengzon of the Court of Appeals in 1963 and, thereafter, upon the appointment of the latter to the Supreme Court in 1964, as his Private Secretary
Justice Azcuna taught International Law at his alma mater, Ateneo de Manila, from 1967 to 1986. In 1982, he completed post-graduate studies in International Law and Jurisprudence at the Salzburg University in Austria.
Representing Zamboanga del Norte, he was elected as member of the 1971 Constitutional Convention. Subsequently, he was appointed as a member of the 1986 Constitutional Commission. He held several government posts during the term of President Corazon C. Aquino, first as Presidential Legal Counsel, then as Press Secretary and subsequently as Presidential Spokesman. In 1991, he was appointed Chairman of the Philippine National Bank. On October 17, 2002, he was appointed Associate Justice of the Supreme Court by President Gloria Macapagal-Arroyo.
Justice Azcuna’s major publications include “International Sales of Goods,” “Transnational Law Practice,” “International Law Teaching in the Philippines,” “Doing Business in the Philippines,” “Foreign Judgment [Monetary] Enforcements in the Philippines,” “Piercing the Veil of Corporate Entity: From Willets to Santos,” “ASEAN Conflict of Law,” and “The Supreme Court and Public International Law.”
In 2007, Justice Azcuna was conferred the Metrobank Foundation Professorial Chair in International and Human Rights Law for which he delivered a presentation entitled, “International Humanitarian Law: A Field Guide to the Basics.”
Justice Azcuna delivered a presentation entitled, “The Writ of Amparo: The Philippine Experience So Far,” as the first recipient of the Founding Chancellor Emeritus Justice Ameurfina Melencio-Herrera Award for the Most Outstanding Professorial Lecturer.
As a holder of the Chief Justice Artemio V. Panganiban Professorial Chair on Liberty and Prosperity, Justice Azcuna delivered a presentation entitled, “Supreme Court Decisions on the Economic Provisions of the Constitution” on April 18, 2013 at the Ateneo School of Law.
Justice Azcuna is married to Maria Asuncion Aunario, a professor of St. Scholastica’s College. They have four children: Anna Maria, Ma. Beatriz, Ma. Margarita and Miguel Enrique.
Source: SC Public Information Office
Since the creation of the Philippine Supreme Court in 1901, no presidential appointment of a Supreme Court Associate had ever been nullified by the High Tribunal. But on July 3, 2007 Azcuna's judgment made history. The Court granted the petition of two foundations that sought to block Gregory S. Ong’s appointment over the citizenship issue. Azcuna wrote that Ong would be unable to join them on the bench "until he had proven in court that he was a natural-born Filipino citizen and corrected the records of his birth and citizenship". The court declared its decision to be final and effective immediately.Republic of Indonesia v. Vinzon (2003) — on a foreign state's immunity from suit
Tecson v. COMELEC (2004) - Separate Opinion — on the nationality of presidential candidate Fernando Poe, Jr.
MWSS v. Hon. Daway (2004) — on corporate rehabilitation of MWSS
Chavez v. COMELEC (2004) — on scope of advertisement ban covering candidates for senatorial candidates
Abello v. CIR (2005) — on taxability of political contributions for donor's tax
ABAKADA v. Ermita (2005) - Concurring and Dissenting — on constitutionality of 2005 Expanded Value Added Tax Law
BAYAN v. Ermita (2006) — on constitutionality of rally permit requirement and policy of calibrated preemptive response
Lambino v. COMELEC (2006) - Separate Opinion — on people's initiative as a mode to amend the Constitution