A member of the Radical Civic Union, Gil Lavedra served as Minister of Justice during the early presidency of Fernando de la Rúa, from 1999 to 2000.

His cross-examination of both witnesses and defendants reportedly focused on exploring the extent of criminal organizations that existed among the Dirty War perpetrators.

Subsequent revelations that the administration had bribed a number of UCR senators for their support of a stalled labor law flexibilization bill in April 2000 led to Gil Lavedra's resignation (as well as that of Vice President Carlos Álvarez and three other cabinet members) in October.

[4] He also served as legal advisor for the United Nations Development Programme, and is a member of the Permanent Assembly for Human Rights and other Argentine jurisprudence associations.

[7] His son, filmmaker Nicolás Gil Lavedra, announced the production in 2011 of Estela, a biographical film on the life of Grandmothers of the Plaza de Mayo leader Estela Barnes de Carlotto[8] (whose testimony the elder Gil Lavedra took as part of the Trial of the Juntas in 1985).