"Addiction," as understood in this paper is the definition used by the World Health organization: "a syndrome manifested by a behavioral pattern in which the use of a given psychoactive drug, or class of drugs, is given a much higher priority than other behaviors that once had higher values." The term "addictive liability," as used throughout this paper, means the likelihood that use of cocaine will be followed by addiction in the sense of a behavioral disorder as described in the aforementioned definition of "addiction." Animal research, clinical studies, survey research, and community studies suggest that patterns of cocaine use vary widely, from occasional experimentation to regular, compulsive use that dominates the life of the user. The evidence reviewed indicates that the likelihood that cocaine users will become addicted has been greatly overstated. Careful estimates of the proportion of those who try cocaine that progress to more intensive use converge around 5 percent to 10 percent. Of individuals in the more frequent use category, a reasonable estimate of those who progress to compulsive use, at some time, is between 10 percent and 25 percent. Those who use weekly or more often are at greatest risk of becoming compulsive users, as are those who begin to inject or smoke cocaine. An effective prevention program must convey the real risks of cocaine addiction in a way that is credible to current and potential users. Moreover, unwarranted preoccupation with the addictive liability of any particular drug may cause society to overlook the deeper structural problems that cause so many people to abuse a drug. The authors conclude by noting that their estimate of cocaine's addictive liability must remain tentative, however; they give reasons for this conclusion. 67 references