"Jesus of Nazareth: The Infancy Narratives" has a print run of 1 million copies, CNN reported. It is being published in the languages of the major Catholic countries: Italian, German, Croatian, French, English, Polish, Portuguese and Spanish.
Benedict, who was known as a scholar before he became a high church official, has already published books on Jesus' life as an adult and on his ministry.
In the book, Benedict examines the evidence the traditional date of Jesus' birth is off by several years. He also says many of the beloved features of Nativity scenes -- the animals gathered around the manger and angels singing overhead -- are later traditions with no basis in the Gospels.
The book is already being distributed in 50 countries. The Vatican said plans call for translations into 12 more languages and distribution in 72 countries.
Monsignor Philip Whitmore, the English translator, said Benedict wants to show readers the "inner meaning" of the Gospel descriptions of Jesus' birth and childhood.
"The pope helps us to understand the world where Jesus was born. Caesar brought peace to the Roman Empire, but this tiny child brought something much more wonderful: God's peace, eternal life, an end to sin and death," Whitmore said. "Anyone who's wondering why Christmas came to be such a great celebration in the West can find the answer right here. The pope explains how the birth of Jesus changed history forever."
Alessandro Speciale of Religion News Service told CNN the pope does not want to censor traditional depictions of the Nativity.
"The pope is a traditional man and he doesn't want people at all to change their traditions," Speciale said.