MONTEVIDEO (Sputnik) — The voting, which began at 8.00 a.m. local time (11:00 GMT), will mark a break with 12 years of rule under Cristina Kirchner and her late husband and predecessor, Nestor Kirchner.
Under the Argentinian Constitution, President Cristina Kirchner, who has served two consecutive presidential terms cannot run again.
Six candidates are competing for the presidency, including front-runner Daniel Scioli, the governor of Buenos Aires province.
A presidential candidate must gain support of at least 45 percent of votes to win the elections.
Thirty-two million of Argentinians are eligible to elect president, vice-president, half of the country's lower house of the parliament along with one-third of its upper house, and 43 lawmakers to Parlasur, the Mercosur bloc's legislative body.
Eleven Argentinian provinces will also hold elections of governors, vice-governors, lawmakers and senators to provincial legislative bodies.
First official results are expected after 10 p.m. local time. The final results are due to be announced on Monday morning.
