While there was no official word about what transpired in the over two-hour meeting, official sources told PTI that they discussed "general security, law and order situation, Karachi operation, different anti-terror legislation and other matters of mutual interest".
PPP senator Raza Rabbani said several issues including the trial of former army chief Musharraf were discussed.
Both leaders held delegation-level talks before heading for lunch.
Federal ministers Ishaq Dar and Zahid Hamid assisted Sharif and senior PPP leaders, including Khurshid Shah and Rabbani, accompanied Zardari.
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Zardari arrived at the premier's house by helicopter and was welcomed by Sharif at the door before the two political rivals proceeded with the meeting.
This is the second meeting between the two since the PML-N took over the reins of government from Zardari's Pakistan Peoples Party (PPP) last year.
The first meeting took place in January this year when the two leaders jointly performed the ground-breaking of the USD 1.6 billion Thar coal power project.
"The meeting will give a message that the country's political forces are united," the unnamed official was quoted as saying.
PPP leader Farhatullah Babar had yesterday extended his party's support to the PML-N government against any "undemocratic adventurism" saying he feared that the ongoing row could threaten the civil dispensation.
The current tension between the civilian authority and the army is primarily because of the Musharraf trial.