[3] On 24 January 2014, Napoli's official website posted that Andújar was in Naples completing a medical in preparation for his move to the Italian club.

On 24 April 2015, Andújar led Napoli to the Europa League semi-finals with a solid performance against VfL Wolfsburg.

[7] On Sunday, 20 March 2022, after Estudiantes' draw against Gimnasia at the Juan Carmelo Zerillo Stadium, for the Professional League Cup, Mariano Andújar became the fifth player with the highest number of appearances in the club's history, with 363 official matches played, and the first in the goalkeeper position.

Andújar made his debut for the Argentina national team in a 2010 FIFA World Cup qualifier against Colombia on 6 June 2009.

[10] During the 2010 FIFA World Cup and 2011 Copa América, Andújar served as understudy to Sergio Romero, the first choice goalkeeper for the Albiceleste.