Born Maximo Antonio del Rosario on November 3, in Higuey, a small town east of Santo Domingo, Dominican Republic, Toño's musical interest started early in his childhood. Using bottlenecks, tin cans and other improvised instruments; Toño and his brothers began entertaining their neighbors.

Toño, together with his brothers Pepe, Tony, Luis, Francis, Rossi formed the group Los Hermanos Rosario (The Rosario Brothers). Sharing leadership responsibility with his brother Rafa, Toño helped manage the band and musical direction and became the group's lead singer.

The group reached enormous success in the local market as well as in Puerto Rico, Spain, Curacao, Panama, St. Martin, and throughout major cities in the United States.

Toño spent twelve consecutive years with the group and released six long-playing albums. Wanting to start a new merengue band, he debuts as a solo artist in Puerto Rico on April 14, 1990 at the Roberto Clemente Coliseum where he initiated a new merengue era, the "Era of Toño Rosario." His first solo album " Toño y Mas" went gold and critics praised the originality of his interpretive style and above all, his undeniably catchy rhythm.

For over a decade Toño has released a number of gold and platinum albums and held a position for thirty-one consecutive weeks in Billboard Magazine in the Latin Music category.

His participation in the Festival Presidente de la Musica Latina held in Santo Domingo, hailed him as the undisputable king of Dominican merengue music.