The aim is to stop the smuggling of drugs and weapons into the country, as well as halting illegal migration from Haiti.
The Dominican Republic has started building a wall stretching around 122 miles (196km) along its border with Haiti.
Luis Abinader, president of the Dominican Republic, said the barrier - which will cover almost half of the country's border with haiti - will attempt to stop illegal migrants crossing the border from Haiti, as well as preventing drugs and weapons being smuggled into the country.
The first phase of the project is expected to be completed within nine months, he said.
It comes a week before the anniversary of the Dominican Republic's independence from Haiti on 27 February 1844.
The project will include the construction of 70 watchtowers and 41 access gates for patrolling.
Despite the two countries being neighbours, they are worlds apart in terms of development.
Haiti is one of the poorest nations in the Caribbean, whilst the Dominican Republic has become a popular tourist destination, with around six million visitors each year.
"The benefit for both nations will be of great importance," Mr Abinader said, adding the border wall will also help fight organised crime in the two countries.
The 20-centimetre-thick concrete structure will be topped by a metal mesh and fitted with cameras, motion sensors and radars.
During the last year, Haiti has battled with gang violence, earthquakes, and the assassination of President Jovenel Moise.
Around 500,000 Haitians and tens of thousands of their descendants live in the Dominican Republic, a Spanish-speaking nation of about 11 million people, according to...