Atsushi Abe, Yuka Iguchi, Rina Satō, and Satomi Arai reprise their audio drama roles and are joined by cast members Shizuka Itō, Kishō Taniyama, Anri Katsu, Kimiko Koyama, and Nobuhiko Okamoto.

[1] In June 2008, an anime television adaptation of Kazuma Kamachi's A Certain Magical Index was confirmed through a promotional sleeve wrapper of the light novel's 16th volume.

[21] Atsushi Abe, Yuka Iguchi, Rina Satō, and Satomi Arai reprise their respective roles from the drama CD of the series, which was released in 2007,[22] as Toma Kamijo, Index, Mikoto Misaka, and Kuroko Shirai.

[23] The main cast also includes Shizuka Itō as Kaori Kanzaki, Kishō Taniyama as Stiyl Magnus, Anri Katsu as Motoharu Tsuchimikado, Kimiko Koyama as Komoe Tsukuyomi, and Nobuhiko Okamoto as Accelerator.

These include Micah Solusod as Kamijo, Monica Rial as Index, Brittney Karbowski as Misaka, Alison Viktorin as Shirai, Morgan Garrett as Kanzaki, Robert McCollum as Magnus, Newton Pittman as Tsuchimikado, Jad Saxton as Tsukuyomi, and Austin Tindle as Accelerator.

[29] In August 2008, Iguchi hosted a talk show event alongside Eri Kitamura, who voiced Ami Kawashima from Toradora!, at the 74th Comiket in Odaiba to promote their series.

[53] Nicole MacLean of THEM Anime Reviews was critical of the show's characters, describing Toma Kamijo a "boring and ineffective lead", the bond between him and Index "staler and shallower" than Toradora!