Millions of Egyptians are going to the polling stations to freely choose their first president since last year's removal of long-time ruler Hosni Mubarak.
After decades of authoritarian rule, people waited patiently in long lines across the nation.
Thirteen candidates, who include Islamists, liberals and Mubarak regime figures, are contesting the election. No outright winner is expected to emerge from the two-day vote so a run-off between the two top finishers will be held on June 16 and 17. The winner will be announced on June 21.
For most of his 29-year rule, Mubarak - like his predecessors - ran unopposed in yes-or-no referendums.
Rampant fraud guaranteed ruling party victories in parliamentary elections. Even in 2005, when Mubarak let challengers oppose him in elections, he ended up not only trouncing his liberal rival but jailing him.
Egypt's next president will be the nation's fifth since the monarchy was toppled following a 1952 coup that ushered in six decades of de facto military rule. Like his three predecessors - Anwar Sadat, Gamal Abdel-Nasser and Mohammed Naguib - Mubarak has a military background.
Many of the candidates in the race have called for amendments in Egypt's 1979 peace treaty with Israel, which most Egyptians continue to view as their nation's number one enemy.
Though none is likely to dump the pact, a victory by any of the Islamist or leftist candidates could mean strained ties with Israel and a stronger backing for the Palestinians in the peace process.
The generals who have taken over from Mubarak after an 18-day uprising forced him to step down 15 months ago have promised to hand over power by July 1, ending a turbulent transitional period defined by deadly street clashes, a faltering economy, a dramatic surge of crime and human rights abuses.
The military has said it has no intention to cling on to power, but it is not clear what authority it wants to retain after the election of a new president. The generals have said they have no preferred candidate, but they are widely thought to be favouring Ahmed Shafiq, a former air force commander and Mubarak's last prime minister who has steadily gained in opinion polls over the past week.
Other front-runners are Mubarak's foreign minister of 10 years Amr Moussa, Mohammed Morsi of the powerful Muslim Brotherhood and Abdel-Moneim Abolfotoh, a moderate Islamist whose inclusive platform has won him the support of some liberals, leftists and minority Christians.
The election comes less than two weeks before Mubarak, 84, is due to be sentenced after he was tried on charges of complicity in the killing of 900 protesters during the uprising against his rule. He also faced corruption charges with his two sons, one-time heir apparent Gamal and wealthy businessman Alaa.
Whoever wins will face the unenviable task of having to tackle a host of formidable problems, ranging from the economy, tenuous security and soaring unemployment. The next president will serve a four-year term.