This article offers an update to a similar article published in the same journal in 2001, which compared the use of substances in Australia and the United States using the National Household Surveys of 1995 and 1998. According to the Australian survey, there was a significant decrease in past-year substance use of “any illicit drug” between 1998 and 2001. The United States survey underwent methodological changes that prevent direct comparison of the years 1998 and 2001; however, increases in the use of any illicit drug were noted between 2000 and 2001. Tables display the patterns of use of marijuana, stimulants, cocaine, ecstasy, heroin, and needles by age group and gender. While rates of alcohol and drug use among teenage girls has historically been lower than that among teenage boys, results in 1998 and 2001 in both countries show a marked increase in drug use by teenage girls that now rivals levels of drug use among teenage boys. Surveys in both countries reveal that over 20 percent of teenagers reported binge drinking in the past month. Australians in their 20's reported the highest rates of lifetime and past-year use, while respondents in the United States reported the highest lifetime use in their 30's and 40's, depending on the drug. Past-year use was highest among teenagers in the United States. Perceptions of risk are associated with use levels; in the United States, perceptions of the risk of marijuana use declined and, as such, use increased. The author hopes to use future surveys to compare how perceptions of risk affect use levels in both countries. These surveys indicate that drug treatment services are needed not only for young people, but for aging users as well, especially in the United States. Tables, references