India took delivery of its Awacs aircraft in June
The Pakistani air force says it has acquired the first of four Awacs surveillance aircraft from Sweden to boost its air defences.
An air force statement said the Saab-2000 Awacs aircraft landed at one of the main operating bases on Tuesday.
The statement did not say anything about the cost of the deal and when the remaining three would be delivered.
The acquisition of the Awacs comes after arch-rival India bought its own Awacs systems from Israel in June.
The BBC's Syed Shoaib Hasan in Islamabad says the Saab-2000 aircraft will boost the Pakistani military's early warning capabilities in the event of hostilities with India.
The aircraft can be used to provide information on all three spheres of military conflict - aerial, naval and land based.
Our correspondent says the Awacs planes and advanced F-16 fighter-bombers soon to arrive from the US will provide a qualitative edge to the Pakistan air force against its numerically superior adversary.
Pakistani military officials say the planes also have a greater range than similar aircraft in the Indian military and can be used as airborne command centres in case of a possible nuclear conflict.