Synopsis by Dan Brown himself:

A renowned Harvard symbologist is summoned to the Louvre Museum to examine a series of cryptic symbols relating to Da Vinci's artwork. In decrypting the code, he uncovers the key to one of the greatest mysteries of all time…and he becomes a hunted man.

From Wikipedia:

The Da Vinci Code is a mystery/detective novel by American author Dan Brown, published in 2003 by Doubleday.

The novel is based on the controversial premise that there is a conspiracy within the Roman Catholic Church to cover up the true story of Jesus. According to this premise, the Vatican
knows it is living a lie, but continues to do so to keep itself in power.

Dan Brown's novel was a smash hit in 2003, even rivaling the sales of the highly popular Harry Potter series. It spawned a number of offspring books and drew glowing reviews from the New York Times, People Magazine and the Washington Post . It also re-ignited interest in the history of the Roman Catholic Church. As well as re-invigorating interest in the church, The Da Vinci Code has also spawned numerous "knockoffs" (as they are referred to by Publishers Weekly), or novels that have a striking resemblance to The Da Vinci Code, including Raymond Khoury's The Last Templar, and The Templar Legacy by Steve Berry.

It is a worldwide bestseller with more than 60.5 million copies in print (as of May 2006) and has been translated into 44 languages. It is thought to be the eighth best-selling book of all time. Combining the detective, thriller and conspiracy fiction genres, the book is the second book by Dan Brown to include the character Robert Langdon, the first being Brown's 2000 novel Angels and Demons. In November 2004, Random House published a "Special Illustrated Edition", with 160 illustrations interspersed with the text.

In 2006, a film adaptation, The Da Vinci Code, was released by Columbia Pictures.

US Mass market paperback with "Now a major motion picture" highlight.