The male couple, in their 40s, sought custody of the teen, who is said to come from a deprived family, the website, TGCOM24, reported.
The men were reported to be “overcome with joy” at the decision by the city’s juvenile court.
Daniela Tomasino, the Palermo president of Arcigay organization, said the ruling is a “signal” that “we are heading towards the normalization of something that is already a reality”.
“Foster care is a way of giving someone the support their family can’t give," she added. "This is what these two men are doing.”
The case follows a similar one in Bologna in November when a judge placed a three-year-old child in the foster care of a gay couple.
The case sparked controversy, but Judge Spadaro at Bologna’s juvenile court said the couple would take good care of the child and offer her a home with “prosperity and peace”.
In Italy, it is illegal for gay couples to adopt but for temporary foster care, the rules are less strict.
According to Italian foster care law, parents can be traditional married couples, preferably with one or more children, or a "family-type community", such as two people filling the function of parents, or even a single person.
In January, the Supreme Court also gave custody of a child to a lesbian couple, although unlike in the latest case, one of the partners was the child's mother.