Stewart was scheduled to host the two-hour event on SiriusXM on Sept. 24. It will feature fans, Nirvana band members Dave Grohl and Krist Novoselic, and Butch Vig, the producer behind "Nevermind." Kurt Cobain, the band's lead singer, committed suicide in 1994.
"Nevermind" was Nirvana's second album and has sold 10 million units in the U.S. The album features the band's biggest hit, "Smells like Teen Spirit."
Grohl is now the lead singer of the Foo Fighters.
SiriusXM will also launch the all-Nirvana channel, Nevermind Radio, on Sept. 23 until Sept. 28.