Dominicans will elect a president, a vice-president, members of both chambers of Congress and municipal councillors - all on the same day.
The last time such a large number of posts was up for election was in 1994.
The elections feature the country's first female presidential candidates and the possibility of President Danilo Medina's re-election.
There are also questions over the vote-counting system.
Because of a constitutional change approved in June 2015, President Danilo Medina has been allowed to seek a second consecutive term.
Mr Medina is presently the front-runner among the eight candidates standing for president with more than 65% of voters saying they intend to vote for him, according to a recent poll by Gallup-Hoy.
The same poll also indicated that 70% believed Mr Medina had greater leadership capabilities than the other candidates.
The polls suggest Mr Medina could become the first candidate to get the 50% of the votes needed to win outright in the first round, eliminating the need for a second round.
The two-round system was introduced by constitutional reform in 1994.