[2][4] In the following years, while working in business, Pérez Yoma was critical of Popular Unity, the coalition of parties that brought the socialist Salvador Allende to power in 1970.

In contrast with his predecessor, Patricio Rojas Pérex Yoma maintained good personal and professional relations with Pinochet, coming to an agreement that his successor in command would be Ricardo Izurieta.

Another situation that Pérez Yoma faced was the removal from the direction of the Carabineros of General Rodolfo Stange, who refused to resign after having been accused of dereliction of duty regarding the Caso Degollados.

Lagos refused to assent to the creation of Punta Peuca, a prison built specifically for the military convicts detained for violations of human rights, whose first occupants were General Manuel Contreras and Brigadier Pedro Espinoza for the murder of former Foreign Minister Orlando Letelier.

In that stint, he created the Mesa de Diálogo (English: Bargaining Table), a body that sought to resolve problems concerning the violation of human rights during the military regime.