Some 7,000 people showed up at the benefit screening of "The Nativity story" in Paul VI Hall, the auditorium regularly used for audiences with pilgrims, although Pope Benedict XVI was not present.
"I think the pope is pretty busy," quipped director Catherine Hardwicke, referring to Benedict's upcoming trip to Turkey.
"The Nativity Story," which opens in the United States and Italy in time for the Christmas holidays on Dec. 1, describes Mary's pregnancy and the trip she and Joseph undertake to Bethlehem, the town of Jesus' birth. It explores Mary's reaction — of fear, doubt and ultimately faith — to what is happening to her.
The film stars as Mary Australian-born Keisha Castle-Hughes, of "Whale Rider" fame, who was not present at the premiere. The 16-year-old star is currently unmarried and pregnant with her own first child.
Hardwicke praised "The Passion," but said she tried to do a more uniting film than Gibson's blockbuster about the last hours of Jesus Christ.
"There were some things he did that maybe were a little controversial. We wanted our film to be uniting and make the public see the similarities between religious instead of the differences," she said.
Before the screening, Archbishop John Foley, a U.S. prelate who heads the Vatican's social communications office, praised what he called a dialogue between faith and culture.
"Cinema, a powerful means of communication, once again carries a universal message," he told the audience.
Some made-for-TV movies have had their premieres at the Vatican. Earlier this year, Benedict watched one of them, "Karol, A Pope Who Remained Man," which explored the life of his predecessor, John Paul II, who died in 2005.
Despite the Vatican's stamp of approval, Hardwicke said her movie sought to appeal not just to religious audiences.
"We hope that people might relate to the relationship in the film, Mary and Joseph, and how their love grows and gets stronger as each one of them has challenges," she said.
Producers said earlier this month that proceeds from the event would go toward the construction of a school in a village that is some 25 miles from Nazareth, the town of Jesus' childhood.
The village, Mughar, whose population includes Christians and Muslims, was one of the Israeli towns hit by rockets fired by Lebanon-based Hezbollah guerrillas over the summer.
"The Nativity Story" is by New Line Cinema, the company that produced "The Lord of the Rings" trilogy.