In 1937, she was placed under contract to MGM and began dubbing the voices of Jeanette MacDonald and Norma Shearer into Italian. She became a narrator for the Voice of America, interviewing American movie stars for broadcast in Italy. At the same time, she made her movie debut in the classic It's a Wonderful Life (1946) as Mrs. Maria Martini.
She wed Miro Brunetti, a foreign correspondent in Hollywood. The two helped to co-found the Hollywood Foreign Press Association. The couple had one son, Mario. Miro Brunetti died in 1966. Argentina Brunetti never remarried.
Brunetti wrote and performed in daily radio shows; she became a member of the Hollywood Foreign Press Association, writing numerous articles on Hollywood personalities; she authored books, wrote music, and appeared in nearly 60 television programmes and almost 70 films. She hosted a weekly weblog on the Internet called Argentina Brunetti's Hollywood Stories, which her son plans to continue running, and wrote a biographical novel called In Sicilian Company. She continued to act into her nineties, most notably as a relative from the Old World who visits and stays with the (wrong) Barone family in a 1999 episode of Everybody Loves Raymond; her last role was in 2002.
She moved to Rome in 2004 to be with her family and died there from natural causes on December 20, 2005, aged 98.