Ginger, the rhizomes of Zingiber officinale Roscoe (Zingiberaceae), has widely been used as a spice and condiment in different societies. Besides its food-additive functions, ginger has a long history of medicinal use for the treatment of a variety of human ailments including common colds, fever, rheumatic disorders, gastrointestinal complications, motion sickness, diabetes, cancer, etc. Ginger contains several nonvolatile pungent principles viz. gingerols, shogaols, paradols and zingerone, which account for many of its health beneficial effects. Studies conducted in cultured cells as well as in experimental animals revealed that these pungent phenolics possess anticarcinogenic properties. This chapter summarizes updated information on chemopreventive and chemotherapeutic effects of ginger-derived phenolic substances and their underlying mechanisms.