Ali Haider Gilani "has been recovered today in a joint operation carried out by the Afghan and US security forces in Ghazni, Afghanistan," Pakistan's foreign office said in a statement.
Afghan National Security Advisor Mohammad Hanif Atmar informed Sartaj Aziz, Advisor to the Prime Minister on Foreign Affairs, about the news in a telephone call, it said.
"Ali Haider Geelani's transfer to Pakistan is being arranged following required medical check-up," it said.
The news of the rescue of Haider, believed to be in his 30s, was broken by Pakistan People's Party Chairman Bilawal Bhutto Zardari on Twitter.
"(former) PM Gilani received a call from ambassador of Afghanistan. His son Ali Haider Gilani has been recovered in a successful operation," Bilawal said.