An AP 1998 file photo of Chastity Bono.
A spokesman for the daughter of Sonny and Cher says Bono "has made the courageous decision to honor his true identity" and began the sex-change process earlier this year.
Publicist Howard Bragman says Bono "is proud of his decision" and hopes "that his choice to transition will open the hearts and minds of the public regarding this issue."
The 40-year-old writer, activist and reality-TV star came out as gay 20 years ago.
