The fifth edition was published in 2003 is a volume with almost 3,000 pages; it contains about 480,000 entries (including 130,000 Japanese headwords, 100,000 compound words, and 250,000 example phrases and sentences), nearly all of which are accompanied by English translations. The editors in chiefs of the fifth edition are Watanabe Toshiro, Edmund R. Skrzypczak, and Paul Snowden.
Besides the print edition, the dictionary is also available on CD-ROM (EPWING format), online, and in electronic dictionary and iPhone versions. Electronic dictionaries that contain the fifth edition are generally flagship models. They include the Canon Wordtank G70, the Seiko SR-E10000 (the first electronic dictionary with GG) and SR-G10000, and the Casio "University Student" series (XD-D9800 in 2012) and "Professional" series (XD-D10000 in 2012).
There is also a companion English-Japanese dictionary, currently in its 6th edition, which contains 260,000 headwords.
In 1918, the publication of the first edition of Kenkyusha’s New Japanese–English Dictionary, Takenobu's Japanese–English Dictionary (武信和英大辞典 Takenobu wa-ei daijiten), named after the editor-in-chief, Takenobu Yoshitarō (武信 由太郎), was a landmark event in the field of lexicography in Japan. Completed in under five years with the assistance and support of leading scholars in the field, and published when Kenkyūsha (研究社) was still a minor academic publishing company, the Takenobu was the most authoritative Japanese–English dictionary of the time, and cemented Kenkyūsha's reputation in the field of academic publishing.
In 1931, Kenkyūsha undertook a major revision in the dictionary by expanding upon former entries and adding newer ones. The British diplomat George Sansom, who later became a renowned historian of Japan, was a major contributor and editor of this edition. Aside from the ever-evolving nature of the Japanese and English languages, competition from two other major dictionaries released in the 1920s – Takehara's Japanese–English Dictionary and Saitō's Japanese–English Dictionary, both of which were larger than the first edition of Kenkyūsha's – was probably a major driving force behind these revisions (although new editions of these dictionaries were never released, allowing Kenkyūsha's to assert and maintain its dominance among Japanese–English dictionaries). From this second edition onward, the dictionary became known as Kenkyusha’s New Japanese–English Dictionary. During World War II, reputable institutions in the United States and Great Britain, including Harvard University's Department of Far Eastern Languages, produced pirated versions of this dictionary for the war effort.