On May 28, 2018, Hernández de Cos was proposed by the Spanish Government for the position of governor of the Bank of Spain, and on May 30 was appointed to the position effective June 11; when he made a promise before Felipe VI of Spain at a ceremony held at Palace of Zarzuela. His appointment was one of the last decisions of the Government of Mariano Rajoy before the vote of no confidence that was successful and resulted in the downfall of Rajoy's government.