The Tuesday court hearing at the National Accountability Bureau (NAB) court in Islamabad kicked off trial proceedings for three of his corruption charges.
Local media said Sharif was scheduled to be formally indicted on October 2, two months after he stepped down.
Sharif left office two months ago after the Supreme Court disqualified him for not declaring a small source of income that he denied receiving.
The Supreme Court has also alleged that the Sharif family’s wealth far exceeds their legal income.
Meanwhile, Sharif’s Pakistan Muslim League-Nawaz (PML-N) party is governing the country and will continue to enjoy majority in the parliament until the next general election due in mid-2018 when the odds could change.
Analysts say negative news from the trials will hurt PML-N’s popularity in the next election.
Sharif, who just returned on Monday after about a month in Britain, told the court his wife, Kulsoom who was recently elected as a lawmaker form Lahore district, was being treated for cancer in London and needs his care.
He did not speak to the media after his court appearance but is due to hold a televised press conference at 3 p.m. local time (1000 GMT).
Sharif has portrayed the corruption claims against him as politically-motivated, while his allies, including daughter and heir-apparent Maryam, have hinted Pakistan's powerful military had a hand in his toppling. The military denies any such action.
“It’s a good thing that finally NAB and such institutions are holding rich and powerful to the count,” said Shafqat Mahmood, a senior members of the opposition Pakistan Tehreek-e-Insaf (PTI) party.
PTI, led by cricketer-turned-politician Imran Khan who spearheaded the legal push into launching a corruption probe against the Sharif family, has called for an early election but it is unlikely the government will agree to that.
Sharif’s return to Pakistan quashed growing speculation that his long absence was the start of another period in exile for the veteran leader whose three stints as prime minister were all cut short, including one by a military coup in 1999.
“What kind of justice is this, what kind of accountability is this?” Sharif told reporters outside his upscale London apartment in London before departing for Islamabad on Sunday.
Two of Sharif’s sons are also due to appear before a NAB court as well as Finance Minister Ishaq Dar, a long-time ally who is married into the Sharif family.
Analysts say Sharif’s return to Pakistan was in large part due to fears of defections within the PML-N, a common occurrence in a nation where politicians switch allegiances ahead of polls depending on which way the political winds are blowing.
Sharif kept control of PML-N after his ouster and installed loyalist Shahid Khaqan Abbasi as prime minister.