Warner, a Democrat, had been testing the waters, visiting Iowa and New Hampshire. But he said it was a tour of colleges with his oldest daughter and a trip to Connecticut to celebrate his father's 81st birthday that convinced him he wants to spend more time with his family, The Washington Post reported.
"I know these moments are never going to come again," Warner said. "This weekend made clear what I'd been thinking about for many weeks -- that while politically this appears to be the right time for me to take the plunge -- at this point, I want to have a real life.
"And while the chance may never come again, I shouldn't move forward unless I'm willing to put everything else in my life on the back burner."
An adviser told the Post that Warner, 51, might consider a presidential run in the future. He said the ex-governor is considering running again in Virginia, which has a one-term-at-a-time limit, in 2009.