This book concerns the native language of the Jews of Shiraz, most of who live in diasporic communities outside of Iran. The language, Judeo-Shirazi, belongs to the Southwest Iranian group, as do most other native vernaculars spoken in southern Iran. None of these languages—unlike other languages of Iranic stock—has been studied in any detail. This is the first novel and detailed look into this language. The author shows Judeo-Shirazi as truly moribund. The result of a ten-year study, this book covers diachrony, phonology, morphosyntax, and lexis, drawn from more than a dozen texts collected from the Shirazi Jewish diaspora living in New York City and Los Angeles areas, as well as unpublished texts collected in Shiraz in 1969, when the speech community was still intact. Conservative as the Shirazi Jewish community is extremely difficult to find speakers who are often old and linguistically isolated. This work draws from immensely valuable videotapes, supported by the Endangered Language Alliance in New York and the Jewish Language Project in Los Angeles. As an ethnically bounded urban language, Judeo-Shirazi is distinct among the Iranic family. Its study is significant within not only Iranic and Indo-European linguistic scholarship but also in Jewish studies.