He also served on several other political positions including Mayor of San Juan from 1969 to 1977 and Resident Commissioner of Puerto Rico in United States Congress from 1993 to 2001.

Romero Barceló, an avid supporter of Puerto Rico statehood with the United States of America,[6] became involved with the "Partido Estadista Republicano", the forerunner of the New Progressive Party, which at the time was led by Miguel Angel Garcia Mendez.

[citation needed] In 1980 he was elected for a second term as governor by a margin of 3,037 votes again over PPD-candidate Rafael Hernández Colón.

In particular, the Puerto Rico Statehood Students Association under Luis Fortuño generated over 1,500 absentee ballots for Romero Barceló that proved an important factor in his re-election.

In his second term Puerto Rico was badly hit by a severe recession starting in 1980 and ending in 1983, the unemployment drastically rose to 25% in 1983 the highest since the Great Depression.

Romero Barceló is frequently associated with the "Cerro Maravilla Incident" of 1978 in which two young pro-Independence activists at Cerro Maravilla were killed at the hands of rogue members of the Puerto Rican Police after being lured by the police to a mountainous area that housed communications and television towers.

In 1984, 10 police officers were indicted and found guilty of perjury, destruction of evidence, and obstruction of justice, with four being convicted of second-degree murder.

After the elections, Romero-Barceló's reaction to the defeat, in response to TV news reporter Rafael Bracero, was ¿Derrota, qué Derrota?

[10] Romero Barceló was hospitalized in San Juan, Puerto Rico[citation needed] in March 2021 for sepsis and a urinary tract infection.

Romero Barceló was a boxing fan, and advocated for holding world championship bouts in San Juan during his terms in office.

Some of his accomplishments were the Minillas Tunnel, the Centro de Bellas Artes Luis A. Ferre, the creation of the Puerto Rico Federal Affairs Administration, and the Roberto Clemente Coliseum (while the Mayor of San Juan).

In 2000, Acevedo accused Romero Barcelo of receiving $175,000 USD of illegal contributions to fund his own campaign bid for Resident Commissioner.