Parliament was dissolved at midnight after completing its term, and a caretaker administration will manage the government until general elections that must take place within 90 days.
Prime Minister Raja Pervez Ashraf was expected to remain in office until the appointment of a caretaker prime minister, a process expected to take a few days.
Pakistan i newspapers noted the historic nature of the changeover in a country known for political upheaval and long bouts of military rule, while attacking the outgoing government's record on the economy and security.
"For the first time in the history of this country, an elected government has completed its tenure in office; and to that extent it can be said that history has been made," said an editorial in The News.
"That truly unfortunately, is only the form. What will be the judgment of history when it studies the content? Will it not reveal it to be a woeful tale of failure -- the failure of our elected leaders to truly make history."
Mr Ashraf defended his government in a televised farewell speech, saying it had launched economic reforms, raised the salaries of state workers and launched development projects.
"It is true that we could not meet the expectations of the people of Pakistan, but we tried our best to control the problems and strengthen democracy," he said.
The government managed to stay in power despite frequent showdowns with Pakistan's powerful generals and an increasingly interventionist Supreme Court that pursued top officials.
The military, which has ruled Pakistan for more than half its 66-year history through coups or from behind the scenes, has long regarded the civilian rulers as corrupt and incompetent.
Army chief General Ashfaq Kayani, however, has vowed to keep the military out of politics and there are no signs the generals are backing any particular party for the poll.
The army, long regarded by Pakistanis as the country's most effective institution, lost face when US special forces killed Osama bin Laden in a unilateral raid in the town of Abbottabad in 2011.
Critics of the government say it missed a valuable chance to capitalise on rare public criticism of the military after that operation to assert civilian rule and demonstrate it was serious about tackling the country's long list of problems.
Western allies have poured billions of dollars in aid into Pakistan, worried that growing public anger over corruption, poverty and energy shortages, may boost recruitment to Islamist militant groups threatening to destabilise Pakistan and beyond.
While the number of Taliban suicide bombings has dropped, the government has failed to contain sectarian violence.
Hardline Sunni groups led by Lashkar-e-Jhangvi have stepped up bombings and shootings of minority Shias, killing hundreds since the start of this year.
The government may soon have to turn again to the International Monetary Fund to keep the economy afloat and avert a balance of payments crisis.