The United States is facing an epidemic of cocaine use by adolescents and young adults from all socioeconomic backgrounds. Epidemiologic data suggest that the use of the drug continues to increase on a year-by-year basis. This is a serious public health problem because cocaine is highly addictive and is associated with a variety of serious complications. In the CNS, these include stroke, intracerebral hemorrhage, vascular spasm, and possibly vasculitis. Seizures and sudden death have been reported. Cocaine use during pregnancy may be associated with fetal hypoxia, intracerebral hemorrhage, and possibly congenital malformations in the neonate. Many of these complications have been recognized only in the last 5-10 years. For example, ischemic changes in the brains of chronic cocaine abusers have been reported only recently. Because even further increases in cocaine use are predicted by drug enforcement officials, it is expected that radiologists will encounter its complications more frequently in the future. Therefore, radiologists should become familiar with the radiologic manifestations of the drug's effects. This article describes the drug's pathophysiology and complications and discusses the evolving role of imaging procedures.