In the early 1950s a Spanish scholar discovered a manuscript in the Vatican Library that turned out to be a 16th-century copy of the long lost Palestinian Aramaic Targum--meaning "translation"--of the Torah, the first five books of the Hebrew Bible. Known as the Targum-Codex Neofiti I, its recovery caused a sensation among Jewish and Christian scholars alike. But reference tools comparable to those available for other targumic texts have thus far been lacking. Fifteen years in the making, this publication is designed to redress that lack. It is based on a complete new reading of both the manuscript and its marginal notes, using facsimile and microfilm editions.