National levels and trends of illicit drug use in the general population are well documented. However, little is known about how this phenomenon is distributed among various subnational areas such as state, metropolitan area, and other local areas. The sample design from the National Household Survey on Drug Abuse (NHSDA) was recently expanded such that estimates from several large metropolitan areas could be produced with reasonable precision. The prevalence of illicit drug use is examined in six large metropolitan areas of the United States. These findings indicate that, in some cases, drug use varies considerably by metropolitan area.