In El Salvador in the late '70s, the wealthy few rule the impoverished many. To maintain the status quo against peasant insurgents and labor organizations, the military regime brutalizes the populace, in particular, rebels who espouse Marxism. Assassinations, executions, and disappearances become commonplace. When the Vatican elevates conservative Oscar Arnulfo Romero (Raul Julia) to archbishop, the military rulers believe he will quiet the masses and the activist priests who support them. "Blessed are the peacemakers," he will preach. At first, that is precisely what he does. But when soldiers thwart voters, shoot indiscriminately into crowds, torture dissidents, and kill a dedicated priest and friend of Romero, the archbishop condemns the regime in radio messages, rebukes quisling bishops, and leads a peasant march into a church occupied by soldiers. He also insults and defies the El Salvadoran president (Harold Cannon), an iron-fisted general, who, ironically, has the same last name as the archbishop Romero, but is not related. The country by this time is in the throes of civil war. In 1980, when military death squads continue their reign of terror even though the government institutes so-called reforms, Romero continues to speak out, gaining international attention. The film then builds to its climax, a scene recreating the events of Monday, March 25, 1980, when Romero is saying mass for his recently deceased mother. Attendees include four men who have no intention of reciting mea culpas or receiving the Holy Eucharist.