Radrizzani made his profession as a member of the Salesians of Don Bosco on 5 January 1968, and was ordained to the priesthood on 25 March 1972.

He was later named Bishop of Lomas de Zamora on 24 April 2001, being installed on the following 23 June.

After six years in the diocese, he was promoted by Pope Benedict XVI to Archbishop of Mercedes-Luján on 27 December 2007.

Radrizzani was the first Salesian and member of any Roman Catholic religious institute to serve as Archbishop of that site.

Agustín Roberto Radrizzani died following a bout with COVID-19 on 2 September 2020, during the COVID-19 pandemic in Argentina.