In 1939 he became Director of Naval Operations and two years later became Franco's under-secretary. In 1951 he was appointed ministerial undersecretary in charge of coordinating the policies of separate ministries. In 1966 he reached the rank of admiral and the following year vice premier. Like Franco he held extreme right-wing views.
In June 1973 he was appointed prime minister. Luis Carrero Blanco was assassinated by ETA, the Basque nationalist organization, on 20th December 1973.