Egyptians are heading to polling stations across the country in the country's first democratic presidential election.
Fifty million people are eligible to cast their ballots, and voter turnout was expected to be high as two days of voting began on Wednesday.
Voters had already formed lines outside some polling stations before they opened at 8am local time (06:00 GMT).
Jamal Elshayyal, reporting from a voting station in the Mediterranean city of Alexandria, where a few hundred women lined up, said there was a "huge euphoria as people are finally getting to choose who will rule the country."
Mounira Fawaz, 21, was one of the early voters. With the little finger on her right hand dyed with purple ink, she told Al Jazeera: "I feel freedom and for the first time, my voice and opinion really counts."
Al Jazeera's Mike Hanna said there was also a high turnout at polling stations in the capital, Cairo, where many people said they had come to vote early to avoid the blistering heat expected later in the day.
The election is the final phase of a tumultuous transition marred by violence, protests and political deadlock, overseen by the ruling military council after a popular uprising toppled longtime President Hosni Mubarak last year.
With none of the 13 candidates expected to secure more than half the votes to win outright in the first round, a runoff between the top two is likely to be in June.
Economy in focus
Among the contenders is former foreign minister and Arab League chief Amr Moussa, who is seen as an experienced politician and diplomat but like Ahmed Shafiq, Mubarak's last prime minister, is accused of belonging to the old
The powerful Muslim Brotherhood's candidate Mohamed Morsi faces competition from Abdel Moneim Aboul Fotouh, a former member of the Islamist movement who portrays himself as a consensus choice with a wide range of support.
Campaigning has been intense in the weeks leading up to the poll, with newspapers carrying interviews and campaign adverts. Banners and posters festoon the streets.
The main issue for voters is the Egyptian economy, which was already stagnant before the revolution and has only gotten worse since.
Nearly half of Egyptians live at or below the poverty line, defined as $2 per day, and youth unemployment is 25 per cent.
Another issue which many voters will consider when choosing their candidate is security, according to Al Jazeera's Rawya Rageh, reporting from the Red Sea port city of Suez,
"In the past 15 months after the revolution, security has been a top concern for Egyptians," she said."There has been lawlessness, all sorts of reports of kidnappings, car jackings, home invasions - the kind of violence this country was never used to."
Our correspondent said questions had been raised "whether the police force, which was discredited during the 18-day revolution, is unable, or simply unwilling, to handle security in the country".
The ruling Supreme Council of the Armed Forces (SCAF), in power since Mubarak's ouster, has called on Egyptians to turn out en masse to the polls, while warning against any "violation".
"The participation of citizens in the presidential election is the best guarantee of the transparency and security of the electoral process," Mohammed al-Assar, a member of the SCAF, was quoted as saying by state news agency MENA.
"We will not allow any violation or [attempt] to influence the electoral process or the voters," he added, saying that any person who broke the law would be treated "firmly and decisively".
The SCAF has pledged to hand power to civilian rule by the end of June, after a president is elected, but many fear its retreat will be just an illusion.
The army, with its vast and opaque economic power, wants to keep its budget a secret by remaining exempt from parliamentary scrutiny, maintain control of military-related legislation and secure immunity from prosecution.
The election comes less than two weeks before a court is expected to issue a verdict in the trial of Mubarak, 84, tried on charges of complicity in the killing of about 900 protesters during the uprising against his 29-year rule. He also faced corruption charges, along with his two sons, Gamal and Alaa.