And Tango Makes Three is the top most controversial book
Authors, artists and musicians are due to gather at a library in San Francisco to protest against the banning of books in schools and libraries in the US.
The event, part of the 27th annual Banned Books Week, has been organised by the American Library Association.
Since 2001 bans on 3,736 books and other materials have been requested.
In recent years, And Tango Makes Three - based on a true story and centring on gay penguins in New York's Central Park Zoo - has had the most ban requests.
The book's authors are Justin Richardson and Peter Parnell.
In a statement to the BBC on Friday, Mr Richardson said: "It's regrettable that some parents believe reading a true story about two male penguins hatching an egg will damage their children's moral development.
"They are entitled to express their beliefs, but not to inflict them on others."
Reasons given by organisations and individuals for their requests to get it removed from public shelves, include "anti-ethnic, anti-family, homosexuality, religious viewpoint, and unsuited to age group".
Other works featuring in the most-challenged books list for 2008 include Philip Pullman's His Dark Materials and Khaled Hosseini's The Kite Runner.
Pullman told Britain's Guardian newspaper that he was glad to be on the list.
However he added: "Of course it's a worry when anybody takes it upon themselves to dictate what people should or should not read."
The association said the aim of the annual awareness week, which ends on Saturday, is to remind US citizens not to take their freedom for granted.
And Tango Makes Three, by Justin Richardson and Peter Parnell
His Dark Materials trilogy, by Philip Pullman
TTYL; TTFN; L8R, G8R (series), by Lauren Myracle
Scary Stories (series), by Alvin Schwartz
Bless Me, Ultima, by Rudolfo Anaya
The Perks of Being a Wallflower, by Stephen Chbosky
Gossip Girl (series), by Cecily von Ziegesar
Uncle Bobby's Wedding, by Sarah S. Brannen
The Kite Runner, by Khaled Hosseini
Flashcards of My Life, by Charise Mericle Harper
Among those at the San Francisco Public Library event will be authors and musicians Ben Fong-Torres, Richie Unterberger and Roy Zimmerman.
They plan to stage a number of performances and defend controversial books.
In 2008 the American Library Association recorded 517 ban and restriction requests. Seventy-four were successful.
The organisation recorded that the most common reason given was that contents were too "sexually explicit".
Other classic literature subjected to complaints include JD Salinger's The Catcher in the Rye, The Great Gatsby by F Scott Fitzgerald and To Kill a Mockingbird by Harper Lee.
The Harry Potter series by JK Rowling also feature on the list.
Earlier this week, it was claimed that Harry Potter author JK Rowling missed out on the Presidential Medal of Freedom because some US politicians believed she "encouraged witchcraft".