More than 9 million registered voters are potentially heading to the polls amid attacks in several cities.
Fourteen candidates are registered but the race will likely come down to incumbent President Ashraf Ghani and his former deputy Abdullah Abdullah.
The winner will play a crucial role in the country’s quest to end the war with the Taliban and any resumption of talks between the insurgents and the United States that were called off earlier this month.
The hardline group, which controls more of the country than at anytime since its regime was toppled in 2001, has threatened voters to stay away from the election or face dire consequences.
To protect voters and polling stations, tens of thousands of Afghan forces were deployed across 34 provinces.
A senior defense ministry official said there were sporadic attacks but the election process was going well.
About 9.6 million of Afghanistan’s 34 million people are registered to vote for one of the 14 candidates at around 5,000 polling centers that will be protected by some 100,000 Afghan forces.
“Bravado gets defined when one musters courage to cast their vote in Afghanistan,” said Roya Jahangir, a doctor based in the capital of Kabul.
Jahangir said she and her husband will vote even if it means standing in long queues for hours.
“We hope this time there is no fraud — otherwise voters will feel cheated once again.”
Media showed lines of men and women outside numerous polling stations, indicating strong turnout in some areas.
In the northern province of Balkh, voters waited for election officials to arrive at polling stations set up in schools, colleges, mosques, hospital campuses and district centers.
An explosion at a polling station in a mosque in the southern Afghan city of Kandahar wounded 14 people, according to a security source. In the northern Faryab province, Afghan forces clashed with Taliban fighters in six districts, forcing people to stay indoors and refrain from voting.
The Taliban said in a statement their fighters attacked polling stations in eastern Laghman province. Officials said four explosions in eastern Jalalabad city disrupted voting at some stations.
Explosions also hit the Afghan cities of Kabul, Ghazni and Jalalabad, officials said, according to Reuters.