Cáffaro began singing gospel while attending elementary school. He started his professional career as a singer in 1959, participating in the Santo Domingo television show La Hora del Moro, hosted by Rafael Solano and transmitted by Rahintel.
In 1961 he made his first recording, Violeta. Later, in 1962, he recorded Juan Lockward's song "Ayúdame a olvidar".
In 1965, Cáffaro continued his career with the hit song "En ruinas", written by Rafael Solano. Later, he recorded a cover of the famous hit song: "Cada vez más".
Cáffaro became more widely known when he won the First Prize Award of the Festival de la Cancion Dominicana in 1968 with Rafael Solano's song "Por Amor". This propelled him to international fame. The next year, he won one of the awards in the first Festival de la Cancion Latina in Mexico Later, in 1973, he won an award in the Festival OTI de la Canción in Brazil. Cáffaro subsequently performed concerts in Puerto Rico, Colombia, the United States, Venezuela, Spain, Curaçao, Aruba and Cuba. He became known as El Señor de los Festivales or "The Festival Master."
Nini Cáffaro is still active as a singer. He currently works for the Cervecería Nacional Dominicana. Cáffaro is married with four children and six grandchildren. His maternal surname Durán is of Haitian origin.
- Niní Cáffaro y Sus Éxitos (1960's)
- Que Grande es el Amor (1960's)
- Por Amor (1968)
- Está Bien (1969)
- Viejo Amigo (1994)
- "Encuentre al haitiano detrás de su apellido "dominicano" consultando esta lista" [Find the Haitian behind your "Dominican" surname at this list]. 7días (in Spanish). 28 September 2013. Archived from the original on 7 December 2013. Retrieved 7 December 2013.