This Introduction to Avestan provides a concise grammar of the Avestan language, the language of the followers of the Iranian prophet Zarathustra. The grammar focuses on spelling, phonology and morphology, but also includes a chapter on syntax. Abundant information on the historical development of the language is included, which renders the grammar very useful for students of Indo-Iranian and Indo-European. Also, a small number of selected Avestan texts is added, with a complete glossary, so that students can practise reading Avestan.