We have the reference that the first inhabitants have origin in the different communities of the southwest such as: Neiba, Duvergé, El Estero, Las Salinas, Azua de Compostela, Santa Cruz de Barahona and other communities, as well as the Haitian immigrants that married or had common-law marriages with Dominicans, forming families in the most populous neighborhood of the community, known as Jimaní Viejo.
By the decade of 1930, Jimaní belonged to Neyba and in 1938, became a section of the commune of La Descubierta and Duvergé, all of them being part of the Province of Neiba, later to be known as Baoruco. At that time, Jimaní was not recognized by the historians and it did not even figured in the map of the Dominican Republic, appearing only Arroyo Blanco and La Furnia, which do not survive to the present day.
Due to its border location, Jimaní became part of the strategic plans of Dictator Rafael L. Trujillo Molina for "Dominicanization" of all the region of the border with Haiti, which resulted in the genocide of thousands of Haitians by Trujillo's agents known as the Parsley Massacre.
After a phase of moderate development, Law 299 of 1943 raised Jimaní to the category of Municipal District, belonging to the commune of La Descubierta.
In 1948, Jimaní became a municipality. Dictator Rafael L. Trujillo Molina wanted to turn it into a more beautiful and magnificent city. At that time many concrete buildings were made for soldiers and public officials brought from the interior of the country to assume public duties, due to the lack of local qualified personnel and widespread low literacy levels in the community
