After his two-act opera El mensajero de plata, to a libretto by Myrna Casas, had premiered at the Interamerican Festival in San Juan on 9 October 1986, Sierra came to prominence in 1987 when his first major orchestral composition, Júbilo, was performed at Carnegie Hall by the Milwaukee Symphony Orchestra.
On February 2, 2006 Sierra's Missa Latina, premiered at the Kennedy Center, in Washington, D.C., conducted by Leonard Slatkin to considerable acclaim.
Sierra's Concierto Barroco takes its inspiration from a scene in Alejo Carpentier's novel of the same name in which Handel and Vivaldi jam with a Cuban slave during the Venice Carnival.
In 2011, UMG’s EMARCY label released Caribbean Rhapsody featuring the Concierto for Saxophones and Orchestra commissioned and premiered by the DSO with James Carter.
In 2010, Missa Latina's Naxos recording was nominated for a Grammy Award under best contemporary classical composition category, and his Sinfonia No.
The award states: "Roberto Sierra writes brilliant music, mixing fresh and personal melodic lines with sparkling harmonies and striking rhythms.