[2][3] He began his professional life at the Bank of Bilbao and became a professor at the University of Valladolid, there obtaining the chair of Public Finance and Tax Law.
Sánchez Asiaín served as President of the Museo del Prado in Madrid, from 1990 to 1993, and the COTEC Foundation, whose purpose is to stimulate innovation in the Spanish industry.
[4] Although due to retirement not performing anymore the profession as a banker, he remained Honorary President of BBVA Foundation.
He was also an advisor to several Spanish and foreign organizations, notably the Vatican Institute for Works of Religion, the Social Council of Technical University of Madrid, the Spanish Foundation against Drug Addiction and the Colegio Libre de Eméritos Universitarios de Madrid (a foundation to support academics in retirement).
He was elected to medalla nº 6 of the Real Academia de la Historia on 20 October 1989, he took up his seat on 8 April 1992.