Ravigupta's Aryakosa is the most important and valuable among the eight niti works that have been translated into Tibetan. It is a collection of 145 stanzas all of which, perhaps with the exception of the last stanza, no. 145, were composed in the Arya metre, which gave the work its title. The work is available only in its Tibetan translation which was done in the ninth century AD and later incorporated into the Tanjur. Prof. Michael Hahn started working on this text as early as 1981 but did not publish it since there were many problems, which remained unsettled. After the publication of the Sanskrit text of Ravigupta's another niti text, namely Lokasamvyavaharapravrtti he could find Sanskrit originals of all but two verses of the Aryakosa. The text presented here is based on the edition and English translation prepared by Prof. Hahn. It includes the Tibetan text of the Aryakosa together with the Sanskrit originals as found in the Lokasamvyavaharapravrtti accompanied by their English translations.