The present volume is closing a gap of the specialist literature felt for some time, because the glossaries and dictionaries available cover the Old Persian vocabulary only in part and are defective in some respects. For preparing a new Old Persian dictionary the situation is quite favourable at present, since a complete edition of the royal inscriptions has been published in 2009 by the author in his book “Die altpersischen Inschriften der Achaimeniden” (Wiesbaden 2009), where only some texts of minor relevance, the inscriptions on vessels, seals (and sealings) and weights, had been ignored. A dictionary like the present comprehensive work probably never had been tackled before for a corpus language like Old Persian, for in order to cope the divergent needs of all sorts of users it contains six separate lists or indexes: lists of (1) the transliterated and (2) the transcriptional word-forms (this one giving a short grammatical definition and a list of all references), (3) the lexicon proper, arranged by word-stems, roots etc. and giving a translation as well as short information about the (syntactical, phraseological or other) use of the word and its etymology, and finally (4–5) reverse indexes of the first two lists and (6) of the dictionary itself (verbal roots, nominal and pronominal stems and indeclinable words being kept apart).