In the mid-1980s a new, smokable form of cocaine, called crack, was introduced in the United States. Soon thereafter, it became apparent that crack cocaine abuse was a serious and important public health concern. Over the past several years, crack cocaine use has increasingly been associated with a myriad of immediate and long-term adverse effects. During this same period, crack cocaine use has progressively moved away from experimentation and recreational use to chronic and compulsive drug use.