This study established validity evidence for scales that assess perceived public stigma and stigmatization of illicit drug use. These concepts were measured with respect to five commonly used drugs: marijuana, powder cocaine, ecstasy, and nonmedical use of opioids and amphetamine. Data were collected from a diverse sample of 1,048 emerging adults in New York City in 2009. Exploratory and confirmatory factor analyses suggested two distinct factors, which were inversely related to exposure to users and recent use of each drug. These measures demonstrated good criterion, construct, and incremental validity and effectiveness in analyzing predictors of use. Study limitations were discussed.