[4] Narvasa graduated magna cum laude from the University of Santo Tomas Faculty of Civil Law, and placed second in the 1951 Philippine Bar Examinations, with a bar rating of 91.6%[5] Narvasa taught at the University of Santo Tomas Faculty of Civil Law.

As general counsel, Narvasa meticulously pieced together evidence to point out the military in the Aquino-Galman murders.

President Corazon Aquino appointed Narvasa as associate justice of the Philippine Supreme Court on April 10, 1986.

Narvasa administered the oath of office during the inaugurations of Philippine presidents Fidel V. Ramos and Joseph Estrada.

Married to Janina Yuseco, Narvasa has six children: Andres, Jr., Raymundo, Gregorio II, Socorro, Martin, and Regina.