The 51-year-old "Achy Breaky Heart" crooner and his soon-to-be ex released a statement through a publicist asking for privacy.
"This is a personal matter, and we are doing what is in the best interest of our family," the statement said. "We ask that you respect our privacy at this time."
The couple has five children, including Miley Cyrus.
Tish Cyrus cited "irreconcilable differences" in her filing, submitted to Los Angeles County Court Thursday. She requested spousal support and attorney's fees.
The couple separated in October 2010 and later reconciled.