"Certainly he is not in Pakistan" Gilani told CNN on a visit here to attend the Nuclear Security Summit.
Gilani said that if he had been in Pakistan he could have been possibly killed during the military operations.
"Our military operations have been very successful... and if Osama was hiding in these areas he could have been nabbed...I don't know whether he is alive or dead," he said.
In line with Indian Foreign Secretary Nirupama Rao's statement on Taliban, Gilani said that he was not in favor of holding talks with the terror group.
"Because at times we talk of good and the bad Taliban. I have always believed that militants are militants. We hardly discriminate between the good Taliban and the bad Taliban", Gilani said.
He said that the militanst were only concerned with destabilizing the political system of the country.
"Our people have let it be known they will not allow handful of extremists and terrorists to intrude our peaceful way of life and inclusive culture," he said.
Gilani said that Pakistan was willing to share actionable intelligence or credible information regarding Osama with the US.
The Pakistan Prime Minister refuted a US media report that ISI is still maintaining links with Taliban, al-Qaeda and other terror groups, adding that Pakistan was cooperating with the US in tackling terrorism.
"In fact, we are having excellent cooperation, in the field of intelligence and defence between the US and Pakistan, and we have jointly and even separately had identified the targets, we got them arrested and they are now facing the courts," he said.
He also denied Washington Post report that Pakistan has secretly released two high-ranking Taliban.
"That would be done by the court," he said, adding that Pakistan has its own laws.