COCA has been an integral part of the cultural life of Bolivia since pre-Incaic times.' Various segments of the indigenous population chew it to cure a variety of ailments, and it is highly praised as a general stimulant. The production of coca in Bolivia has increased significantly in recent years, yet there is no evidence that the incidence of coca chewing is growing. Indeed, many observers believe the use of coca is declining as the forces of modernization shift it from a generally accepted stimulant into the realm of a social stigma. If the increase of Bolivian coca production is not the result of an indigenous demand for the leaf, then it is an attempt to meet an international demand for coca derivatives, namely cocaine. Cocaine use in the United States, for example, is currently the nation's most serious hard drug problem as measured by the number of arrests for hard drug use and by the number of seizures of large amounts of cocaine.2 The demand for coca to produce cocaine is having a significant impact on the entire coca system in Bolivia. Crop controls on coca are being considered as a result of the increasing numbers of cash-crop farmers whose success can be noted in production statistics. The coca-chewing population may find it increasingly difficult to compete at the marketplace as coke producers affect both the general patterns of coca distribution and the ability of a chewer to sustain his habit.3 This paper is concerned with the use of coca in Bolivia and some of the implications of an illegal external demand on a traditional cash-crop and marketing system.