Jaime Diaz was born on January 6, 1937 in Saenz Pena, Chaco, Argentina as Jaime Reyes Diaz. He grew up in a small farming community and studied art in college. After watching the Droopy cartoon Dumb-Hounded, Diaz decided to immigrate to the United States and become an animator. He arrived in November 1963 with his wife.
Shortly after settling in the United States, Diaz met famous animator Tex Avery, who hired him to work for Cascade Films of California. Diaz provided his first animation for director Friz Freleng and worked as a layout artist for Bob McKimson at Warner Bros. for Daffy Duck and Speedy Gonzales shorts. He remained with the studio through the late 1960s.
In 1971, Diaz was an assistant animator on the television series The Curiosity Shop, where he met and befriended fellow assistant Larry Huber.Other work throughout the decade included providing layouts for Hanna-Barbera, worked at Ralph Bakshi's studio and worked with Filmation under several positions, ranging from storyboard artist and character designer. While at Filmation, he worked closely with future director Don Bluth.
Diaz returned to his native Argentina with his wife and children in 1983, living in Buenos Aires.There, he founded his own animation and art studio, Jaime Diaz Productions, which had been a lifelong dream of his. The company was run by him and other family members. With his studio, Diaz produced comic books for Disney, published artwork in Europe and provided animation for local commercials in Argentina advertising products in addition to being an overseas animation studio for Hanna-Barbera.
By 1992, Jaime Diaz Productions provided animation contracting services for several series, including Fish Police. Diaz began working on a short film, Gaucho Pampa, during the 1990s, though the film was left unfinished when Diaz and his family returned to the United States in 1995.Soon after, he began working for Klasky-Csupo as a director on Duckman and worked on The Rugrats Movie in 1998. He joined Frederator Studios near the end of the 1990s, working on ChalkZone and The Fairly OddParents through the early 2000s.
In 2002, Diaz managed production technology at Klasky-Csupo. With longtime friend Larry Huber, Diaz co-founded Magic Lantern Productions.Huber also helped Diaz finish Guacho Pampa in 2007. Diaz was still active in animation at the time of his death, having returned to Frederator in the mid-2000s and directing episodes of Danger Rangers.
Throughout his career, Diaz was the recipient of several awards: receiving a Clio Award, Lapiz de Oro for his commercial work and was honored with a Silver Lion (Leone d'Argento). For his work on the ChalkZone pilot, "ChalkZone," Diaz was nominated for an Annie Award in 1998, in the category of "Outstanding Individual Achievement for Directing in an Animated Television Production."
Huber recalled that Diaz had a reputation for being a perfectionist, and this trait often put him at odds with ChalkZone's production managers, due to Diaz's tardiness. Huber defended Diaz, claiming there would be no retakes to make up for the money lost during Diaz's episodes. Sure enough, his episodes returned from the overseas animation studio with no retakes required.