Bruce Jenner interview: 'It's going to be an emotional rollercoaster'
It's widely speculated that Bruce will use the two-hour interview to publicly confirm widespread rumours that he is transitioning into a woman.
Bruce recorded the interview with Diane Sawyer earlier this year, and it will air on US TV tomorrow night.
Trailers released in the past days have included clips of Bruce saying his family are the most important thing to him and he cannot let them get hurt.
Bruce has never publicly addressed the speculation he is becoming a woman, speculation that heightened yesterday when a New York newspaper claimed to have the first images of Bruce wearing a dress.
The Olympian split from Kris Jenner two years ago. They have two children together: Kendall, 19, and Kylie, 17. Bruce also has four other older children, and is stepfather to Kim, Khloe, Kourtney and Khloe Kardashian.
Rumours that Bruce is transitioning into a woman have been circulating for quite a while, fuelled by his changing appearance including longer hair and wearing nail polish.
Stepdaughter Kim Kardashian West refused to confirm or deny the claims in an interview earlier this year, saying that it was Bruce's story to tell when he was ready.
But Bruce's mum appeared to confirm the rumours, telling The AP of the moment Bruce told her: "It was brief and I said I was proud of him and that I'll always love him. I never thought I could be more proud of Bruce when he reached his goal in 1976, but I'm more proud of him now. It takes a lot of courage to do what he's doing."
For exclusive competitions and amazing prizes visit Reveal's Facebook page NOW!