Dacascos' father, Al Dacascos, is from Hawaii, and is a martial arts instructor of Filipino, Spanish, and Chinese ancestry. His mother, Moriko McVey-Murray, is of Irish and Japanese ancestry. In the History Channel presentation, "Samurai", he revealed that many of the Japanese side of his mother's family were killed in the bombing of Hiroshima. His stepmother, award winning martial artist, Malia Bernal, raised him. Dacascos attended Los Angeles Valley College and was on their 1983-1984 Gymnastics Team coached by Gary Honjio. He also attended Portland State University in Portland, Oregon. Dacascos is proficient in his father's style of Martial Art, Wun Hop Kuen Do. He has studied Muay Thai with Kru Puk, Capoeira with Mestre Amen Santo, and Wushu with Coaches Eric and Debbie Chen, though he self-admittedly is still very much a beginner/intermediate student in those arts.
Dacascos became an actor after being discovered walking down the street in San Francisco's Chinatown by Chris Lee (at that time, assistant director) and Rexall Chin (hairstylist) for director Wayne Wang. Though his first scenes ended up on the cutting room floor, he has gone on to establish a film and television career primarily playing martial artists. He was originally set to play as the red ranger in Bio-Man produced by Haim Saban which never got pick up.
His breakout role was in the 1993 film Only the Strong, in which he played Louis, a Capoeira master who takes a high school's potential failures and turns their lives around by teaching them the Brazilian martial art based on the West African martial art brought by slaves. In the following year, Dacascos co-starred with Party of Five's Scott Wolf as Jimmy and Billy Lee, respectively, in the movie, based on the video game, Double Dragon.
Dacascos was nominated for the Saturn Award for Best Supporting Actor in 2002 for his role in Brotherhood of the Wolf. He also appeared in the television series The Crow: Stairway to Heaven, which was a follow-up to the 1994 film The Crow. He also appears in the children's television show, Kamen Rider: Dragon Knight, where he portrays Eubulon, also known as the Advent Master, mentor of the Kamen Riders and creator of the Advent Decks.