The statement reiterated the Catholic Church's opposition to the death penalty.
"The Holy See is following this affair with attention and commitment," Vatican spokesman Federico Lombardi said in a statement issued in answer to journalists' questions on the matter.
Sakineh Mohammadi-Ashtiani, a 43-year-old mother of two, was given the death penalty for an extramarital relationship, sparking a global campaign to spare her.
"The position of the Church, opposed to the death penalty, is known and stoning is a particularly brutal form," he said.
Intervention by the Holy See on humanitarian questions takes place through diplomatic channels, and this sort of action had taken place a number of times in the past, the statement said.
Pope Benedict XVI did not make any mention of the case at the Angelus on Sunday.
SIC: AFP/INT'L