The four candidates will be contesting for the presidential post, Trend reports citing Sputnik.
Hugo Martinez from the left-wing Farabundo Marti National Liberation Front (FMLN); businessman Carlos Calleja from the right-wing Nationalist Republican Alliance (ARENA); former mayor of the country's capital, Nayib Bukele from the conservative Grand Alliance for National Unity (GANA); and Josue Alvarado from the centrist Vamos party are running for presidency.
Incumbent President Salvador Sanchez Ceren cannot run for a second consecutive term under the country's legislation.
Around 1,600 polling stations will be open from 7 a.m. to 5 p.m. local time (from 13:00 to 23:00 GMT). Over 5.2 millions citizens have registered to vote. Security measures will be enhanced, with the country's police, Armed Forces, and prosecution being in charge of it.
To win in the first round, a candidate must secure over 50 percent of the vote. Otherwise, a run-off will be held on 10 March, with two top candidates facing each other. In El Salvador, the president is elected for a five-year period.
According to various opinion polls, Bukele, 37, is the favorite to win the election outright in the first round. However, even if Bukele is elected as the country's president, his legislative room for the political maneuvers could be limited because his GANA party is expected to lack a majority in the country's Congress, Reuters reported.
Bukele is reportedly an active social media user who wants to modernize the local government, introduce infrastructure projects and push reforms to tackle country's economic issues.
According to AP, on foreign relations, Bukele said he would promote strong ties with the United States and also examine all deals between the current government and China. Last year, incumbent president Ceren switched El Salvador's diplomatic recognition from Taiwan to Beijing, a move that prompted Washington to recall its ambassador.
Bukele has studied law at Jose Simeon Canas Central American University but reportedly left before getting a degree.
El Salvador's last six presidents have come from either ARENA or FMLN parties.