Iron is an essential micronutrient for the growth and function of all cells. It is, therefore, an attractive target for chemotherapeutic compounds. Numerous studies in vitro and in vivo provide evidence that iron chelators may be effective antitumor agents. Lipophilic iron chelators that are readily cell permeable and can bind intracellular iron stores may selectively kill cancer cells without damaging normal cells. In this review we discuss the role of iron in cellular processes and how these processes differ between normal and neoplastic cells. We also review the effects on normal and cancer cell growth of several lipophilic iron chelators.