Anger over corruption, the faltering economy and land reform are key issues as South Africans vote in the sixth democratic national election since apartheid ended 25 years ago.
Young people queuing to vote have been speaking of their difficulties in finding jobs, with unemployment at 27%.
The African National Congress (ANC), which led the fight against apartheid, has governed the country since 1994.
But its support has eroded as large inequalities have remained.
The centrist Democratic Alliance (DA) and radical Economic Freedom Fighters (EFF) are providing the main challenges.