Before coming to the United States, Nebres studied fine arts in the Philippines. He later worked for the Filipino comics industry, for such publishers as Bulaklak Publishing, ACE Publications, and Graphic Arts Service (GASI).
Shortly after DC Comics editor Joe Orlando and publisher Carmine Infantino’s 1971 visit to the Philippines to scout talent, Nebres began working for the American comics industry. In 1973 he inked a few stories for DC’s horror titles, including House of Mystery and House of Secrets. From 1973–1977, Nebres worked for fellow Filipino cartoonist Tony DeZuniga’s studio.
Nebres began working for Marvel Comics in the mid-1970s, on such titles as Doctor Strange, Power Man and Iron Fist, Marvel Super Special, and John Carter, Warlord of Mars. He also contributed to Marvel’s black-and-white magazine line, Curtis Magazines, most notably on Deadly Hands of Kung Fu.
From 1980–1983, he worked for Warren Publishing on such titles as Creepy, Eerie, Vampirella, and 1984. (Nebres was part of a wave of Filipino cartoonists, including Alex Niño and Alfredo Alcala, who worked on Creepy and Eerie in the early 1980s.) Following his stint at Warren, Nebres worked for Pacific Comics, and in the mid-1980s he worked for Archie Comics’s short-lived superhero line on such titles as Blue Ribbon Comics. In the late 1980s and into the early 1990s, Nebres worked for Continuity Comics.
In 2000, SQP Inc. published The Art of Rudy Nebres, a collection of fan commissions.