In 1999, Muñoz's got his first professional assignment: shooting a fashion story for British Vogue with Gisele Bündchen. In 2008, Muñoz and Bündchen collaborated to celebrate the 30th anniversary of American Photo magazine. Muñoz has continued to work with Bündchen throughout his career and has photographed some of Hollywood's finest such as, Tom Cruise, Hilary Swank, Leonardo DiCaprio, Julianne Moore, Don Cheadle, Adrien Brody, Maggie Gyllenhaal, Sam Rockwell, Jay-Z, Christina Aguilera, Beyoncé, Daniel Craig, and Jake Gyllenhaal.
In a story on Muñoz called "Coasting West," the photography journal PhotoIcon wrote: "The extensive beaches of Southern California and the glitter of Los Angeles was a spiritual homecoming for Nino Muñoz. His experience of New York's fashion world made the move to photographing the Hollywood celebrity circuit a natural progression—and Nino's natural charm and warm personality has made him a popular society snapper in Hollywood."
He is also an advertising photographer, with clients such as Victoria's Secret, True Religion, Vero Moda, and London Fog.
A selection of Muñoz's photographs were on view in the "Beauty CULTure" exhibit at the Annenberg Space for photography in Los Angeles in 2012.
Muñoz has volunteered his time to the non-profit organization the Art of Elysium, and in 2007, he joined forces with them and French Connection to host an exhibit of his photos, the proceeds of which benefited the Art of Elysium.
Muñoz is represented in the US by Stockland Martel.
In Europe & Asia, Muñoz is represented by Terrie Tanaka Management.