Narvasa taught at the University of Santo Tomas Faculty of Civil Law. Soon, he became a full professor of law, and eventually Dean of the University of Santo Tomas Faculty of Civil Law|Faculty of Civil Law. Narvasa started as a law practitioner in 1952, as head, Andres R. Narvasa & Associates. He then became professor of law, 1952, bar reviewer, 1959, legal counsel, University of Santo Tomas, 1973, dean, Faculty of Civil Law, University of Santo Tomas, 1967–1973, vice-rector for student affairs, University of Santo Tomas, 1969–1972, member of the board of trustees, University of Santo Tomas, 1974 and president of the Faculty Club, University of Santo Tomas, 1969. Narvasa was appointed as the general counsel for the Agrava Fact-finding Commission, formed by then President
Ferdinand Marcos and tasked to investigate the death of former senator and staunch Marcos critic
Benigno Aquino Jr. The commission was chaired by former
Philippine Court of Appeals Associate Justice
Corazon Juliano-Agrava. 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 served as associate justice until his appointment as chief justice on December 1, 1991, also by Aquino. Narvasa administered the oath of office during the inaugurations of Philippine presidents
Fidel V. Ramos and
Joseph Estrada. After his retirement in 1998, he was appointed by President Estrada to serve as chair of the Preparatory Commission for Constitutional Reform, an independent commission formed to study the basic charter and suggest potentially positive modifications. He served in this capacity from 1999 to 2000. In November 2000, Narvasa became counsel for Estrada in his impeachment proceedings before the
Philippine Senate. ==Private life==