"I believe my friend Donald Trump when he tells me he didn't do it," the former New York City mayor and Trump adviser told CNN's Jake Tapper on "State of the Union."
He wouldn't call the Republican nominee's accusers liars outright but said some cases appear "kind of untrue" to him.
"I believe Donald Trump," he said. "I don't know about the nine women. I haven't studied the case. I'm a lawyer. I'd have to study each case to tell you that. I'm not going to engage in Clinton-type conduct in attacking. I'm just telling you that I believe he's telling the truth. I do not believe -- some of these cases appear to me on their face to be kind of untrue."
Giuliani said it's "not true" that Trump has attacked his accusers more viciously than the Clintons criticized Bill Clinton's accusers.
When Tapper pointed out that Trump, in campaign speeches, is "calling them liars and saying they're not good-looking enough," Giuliani demurred.
"I really don't want to dispute this with you. I mean, the four women that I met with tell me that Hillary Clinton was engaged in all types of attacks on them, both public and private," Giuliani said.
The former New York City mayor then tried to turn to the discussion to policy.
"But in any case, shouldn't we be beyond that now? Shouldn't we be beyond Donald Trump's past and Hillary Clinton's past?" he said.
Tapper pointed out that it was Trump who brought three women who had accused Bill Clinton of sexual misconduct to the second presidential debate and featured them in a surprise event beforehand.
"It's not the media making sexual assault an issue. Donald Trump is making sexual assault an issue," Tapper said.
"They asked to come. They asked to come," Giuliani said. "But the reality is, can we get off it? ... I was with Donald Trump all day yesterday. He talked about the women maybe two or three minutes."