Frida Kahlo's tiny Autorretrato en Miniatura is expected to make close to $1.2m at Sotheby's Latin American Masterpieces auction in New York, next month.
The two-inch long oil self-portrait of the Mexican artist sold for $225,750 in 2000 and is one of the leading attractions for art investors at the May 25 sale.
Another miniature work by Kahlo, Survivor, sold for $1.1m at Christie's last year - far surpassing its $150,000 estimate.
The record for a Kahlo work is currently $5.61m. That was paid for the 1943 oil on metal Roots at Sotheby's in 2005.