More than 2,400 candidates are competing for the 249 seats in the Wolesi Jirga, Afghanistan's lower house of parliament.
Elections in 2009 that secured a second term for Afghan President Hamid Karzai were tainted by rampant fraud and corruption.
Fazal Ahmad Manawi, the chairman of the Afghan Independent Election Commission, said during a news conference in Kabul that election materials such as ballots and the ink used to mark voters were improved to prevent tampering.
"If our polling staff applies (the ink) properly, no one will be able to vote more than once," he said.
Staffan de Mistura, the U.N. special envoy, acknowledged that Saturday's elections would be "far from" perfect but expressed a certain degree of cautious optimism.
"We feel they are going to be much better than the previous ones," he told reporters
De Mistura said the U.N. mission in Afghanistan has seen a rise in incidents targeting female candidates, assassination attempts and general political violence, adding insecurity "could be the real spoiler" in the weekend elections.