The musical score of the film “For a Few Dollars More” was composed by Ennio Morricone, who had previously collaborated with director Leone on A Fistful of Dollars. Under Leone's explicit direction, Morricone began writing the score before production had started, as Leone often shot to the music on set. The music is notable for its blend of diegetic and non-diegetic moments through a recurring motif that originates from the identical pocket watches belonging to El Indio and Colonel Mortimer.  "The music that the watch makes transfers your thought to a different place," said Morricone. "The character itself comes out through the watch but in a different situation every time it appears."

A soundtrack album was originally released in Italy by RCA Italiana. In the United States, Hugo Montenegro released a cover version as did Billy Strange and Leroy Holmes who released a cover version of the soundtrack album with the original American poster art. Maurizio Graf sang a vocal "Occhio Per Occhio"/"Eye For An Eye" to the music of the cue "Sixty Seconds to What" track that did not appear in the film but was released as a tie-in 45rpm record.

All tracks written by Ennio Morricone.