According to Forbes, Rainieri has one of the ten largest fortunes in the Dominican Republic, with a net worth near the billion-dollar mark as of 2014.

[5] In 2015, he was designated ambassador of the Sovereign Military Order of Malta to the Dominican Republic, a position that his father also held four decades earlier.

[4] His parents were Francisco Rainieri Franceschini and Venecia Marranzini Lepore (daughter of the Italian immigrants Orazio Michelo Marranzini Inginio and Inmaccolatta Lepore Rodia, who migrated as children with their respective families, all of them natives of Santa Lucia di Serino, in southern Italy).

In 1969, Rainieri and Theodore Kheel[8] acquired a 58-million square meter land on the eastern end of the Dominican Republic, which was covered with jungle and six miles of beach.

[9] In 1997, Rainieri and Kheel partnered with Oscar de la Renta and Julio Iglesias to start work on the Punta Cana Marina and the real estate development of the area.