During the presidency of Ollanta Humala, Cateriano served as Minister of Defense from July 2012 to April 2015. In his almost three-year tenure, he remained a controversial member of Humala's administration, constantly clashing with the opposition regarding the government's modus operandi, in which First Lady Nadine Heredia seemingly interfered with government decisions. He also faced criticism for his support of pecuniary sanctions on voluntary military service enrollment, which the Constitutional Court declared the measure unconstitutional. Upon the resignation of Ana Jara on 2 April 2015, due to her being censured by the Peruvian Congress regarding illegal government espionage under her management as Prime Minister of Peru, Cateriano was appointed as her successor. Seemed by pundits as a government loyalist, he served through the end of Humala's presidency.