Taxol®, a naturally occurring diterpenoid is one of the most exciting antitumor drugs available today. Its current indications (refractory ovarian and metastatic breast cancer) may soon be expanded since the drug is showing activity against lung and head-and-neck cancers. The book opens with a review of the naturally occurring taxoids, a chapter which is not a comprehensive list of all taxoids isolated to date, but attempts a systematic approact to describing the different classes of taxoids, with particular reference to all skeletal types and the various functionality patterns. Biosynthetic studies are also discussed, as well as some of the basic chemistry and common functionalities of taxoidic skeleton. Structural identification of taxoids, mostly by spectroscopic means; the formulation of taxanes; the metabolism and pharmacokinetics of Taxol® are also discussed, as are the chemistry of taxanes in relation to SAR studies; SAR aspects of the phenylisoserine side chain; and the mode of action of the taxanes and the mechanisms of resistance. The book is therefore written for medical chemists, in order to stimulate further research in this area and to provide the reader with the necessary background information to start a research program in the area.