Methamphetamine (also known as "speed," "crystal," "crank," "go," and "ice") is the most widely illegally manufactured, distributed, and abused type of amphetamine, a class of stimulant drugs. An estimated 4 million persons in the United States have abused methamphetamine at least once (1). Information from several sources--including medical examiners, hospital emergency departments (EDs), substance-abuse-treatment facilities, and community epidemiologists--suggests a recent increase in morbidity and mortality associated with abuse of methamphetamine in the United States, primarily in the West but also in the South and Midwest. To characterize trends in methamphetamine-associated morbidity and mortality during 1991-1994, the Substance Abuse and Mental Health Services Administration (SAMHSA) compiled and analyzed data from the Drug Abuse Warning Network (DAWN) and the Treatment Episode Data Set (TEDS). This report summarizes the results of these analyses.