The polling opened at 7:00 a.m. local time (0230 GMT) and will close at 3:00 p.m. (1030 GMT) in the country’s 34 provinces, according to election officials.
It is the fourth presidential election in Afghanistan since 2001, when the Taliban regime was ousted.
A total of 18 contesters are running for the presidency with a five-year term and among the candidates are sitting President Mohammad Ashraf Ghani and government Chief Executive Abdullah Abdullah.
Security remains the biggest challenge for the election.
The Afghan security forces will provide security for 4,942 out of 5,373 polling centers and the remaining 431 centers located in remote districts will not open on the election day due to security threats, according to election officials.
Over 9.4 million eligible voters, 35 percent of them women, registered to cast their votes during Saturday’s polling.