Katsuhiko Nishijima was born on February 4, 1960, in Tokyo and moved to Chiba Prefecture's Funabashi City at a young age. As a student, he aspired to become a manga artist and was an avid fan of Mobile Suit Gundam. After withdrawing from Chiba University of Commerce, he sought a career in animation. While his initial attempt to join Sunrise was not successful, a producer there introduced him to Studio LIVE, founded by Yoshio Ashida, where he was accepted and began his professional training.

Nishijima's early career as an animator is closely tied to the classic series Urusei Yatsura. He was a dedicated fan of the original manga and personally requested to work on the anime adaptation. He joined the production team and contributed as a key animator and storyboard artist, with his first role as an animation director on episode 105 in 1983. During this period, he also co-founded the freelance animator group Studio Graviton in 1984 alongside notable figures like Hideaki Anno.

His debut as a director came with the feature film Project A-ko in 1986. Nishijima served as director, co-writer, and co-original creator for the film. The movie was a comedic and action-packed parody of the science fiction and superhero genres, and it established many of the thematic elements that would come to define his authorial identity. He continued to work on the franchise, serving as an original creator for its sequels, including Project A-ko 2: Plot of the Daitokuji Financial Group.

Throughout the 1990s and 2000s, Nishijima became highly active in the original video animation (OVA) market, a format that allowed for greater creative freedom and more mature content. He directed numerous OVA series, including AIKa in 1997. His work from this period is characterized by a focus on action, espionage, and comedy, often featuring prominent fan service. This artistic identity is fully realized in the 2001 anime television series Najica Blitz Tactics, which he directed. The show follows a secret agent and her android partner, combining gunfights and martial arts with risqué visual elements. The original concept for Najica Blitz Tactics was created by Nishijima, and it was later adapted into a manga by Takuya Tashiro, which was published from 2001 to 2003.

Beyond his original creations, Nishijima has a long and significant history as a storyboard artist and animator for a wide range of other productions. His credits span from the science fiction epic Nadia: The Secret of Blue Water and the Gainax classic Gunbuster to later series like Kill la Kill and High School DxD BorN. He has also directed several other OVA series, such as A-Ko The VS, Graduation, Lingeries, and G-taste, solidifying his reputation for producing entertainment-driven action comedies with a strong emphasis on stylized action and sex appeal.

Katsuhiko Nishijima's significance in the anime industry lies in his consistent output as a director and creator of OVA and television series that prioritize pure entertainment value. His work on the Project A-ko series helped define a style of energetic, parody-driven anime in the late 1980s, while his later projects like AIKa and Najica Blitz Tactics became emblematic of the action-oriented, fan-service laden productions that were a staple of the OVA market in the late 1990s and early 2000s.