The belongings took in $1.6m (£992,000), three times the estimated total expected.
Garbo's sunglasses, furs and Ferragamo shoes were among the items sold, according to The Huffington Post.
"Greta Garbo commanded Marilyn Monroe prices today," said Martin Nolan, executive director of Julien's Auctions.
"Her beauty, extraordinary screen presence and fashion-trending style were proven to be timeless in this extraordinary two-day event."
Garbo is best known for her roles in 1930s productions such as Grand Hotel, MGM's Anna Karenina and the romance Camile.
She retired from the film industry in the 1940s, declining many offers to return to acting and opting to lead a private life.
Garbo died in April 1990 at the age of 84.