Haiti's Civil Protection Office said in a report Tuesday that the bulk of the deaths happened in the southeastern and western departments of the country.
Some of the victims were electrocuted and others died after objects fell on them. Three people are missing.
The death toll has steadily increased in Haiti after Tropical Storm Isaac passed over the southern part of the country Saturday and caused extensive flooding.
Haiti's mountains are heavily deforested and so the country is prone to mudslides that sometimes turn fatal.
The new deaths put the total death toll of Isaac at 29. Five people died in the neighboring Dominican Republic.