The Provisional Electoral Council (CEP) in Haiti, on Monday said only eight candidates won seats outright in the 119 member Chamber of Deputies in the August 9 first round of balloting.
It said only two candidates were successful in the races for the 20 Senate seats.
The CEP said the results of the polls were marred by violence and acts of sabotage.
It said turnout was 18 per cent and that the second round of balloting will take place on October 25.
It said as a result, voting will be held all over again in 24 of the country’s 119 electoral districts.
Political parties have been calling for the resignation of the CEP members and have disputed the preliminary results.
Haiti’s Parliament was dissolved on January 13, 2015 after lawmakers’ terms were not extended, and the legislative chambers have remained empty for months.
President Michel Martelly, who has been ruling the country by decree, will not face the electorate on October 25 when the first round of presidential elections will also take place.
The elections are the first since Martelly came to power in 2011.