Hellsing: Ultimate is an Original Video Animation (OVA) series. The series was created after the Hellsing anime had finished, and was intended to be more true to the manga than the anime was. Over the course of the years, they have changed animation studios at multiple occasions. Hellsing Ultimate 1-4 were animated by the animation studio Satelight, before Madhouse took over as of 5-7. It has recently been announced that a new company would be animating the final three episodes of the series; Graphinica x Kelmadick. It is still being produced by Geneon.
The ending of each episode uses various pieces of instrumental music composed by Hayato Matsuo and performed by the Warsaw Philharmonic Orchestra, up to the fifth installment. Episodes VI and VII feature vocal closing themes by Japanese rock group Suilen, titled "Magnolia" and "Shinto-Shite", respectively. EpisodeVIII has "When You Start the War, Fight With Arrows, Spears and Swords!" a song from the original TV series, and episode IX features Japanse singer Maon Kurosaki in the song "Scars."