A featured part of this report consists of the findings of the authors' study of substance-use disorders among homeless people living in the inner city area of Sydney, Australia's largest city. A total of 210 homeless individuals (160 men and 50 women) agreed to participate in the study. Alcohol dependence was found to be the most prevalent substance-use disorder, affecting 35 percent of homeless persons in the past 12 months. Homeless people were three times more likely to have an alcohol-use disorder than the Australian general population. Dependence on or abuse of other drugs affected approximately one in three persons in the past 12 months, with cannabis and opiates accounting for more drug-use disorders than any other illicit drug. Overall, homeless people were 6 times more likely to have a drug-use disorder and 33 times more likely to have an opiate-use disorder than the Australian general population. Homeless people in Sydney were 3.4 times more likely to have a drug-use disorder than homeless people in comparable studies in both Munich, Germany and Los Angeles, CA. These differences may be related to socioeconomic or political characteristics of the countries. There may be relatively fewer young drug users among the homeless population in Munich and Los Angeles because they are living with their families. The authors note that effective treatments are available for alcohol and drug abusers; the challenge is making them available to the homeless. 1 table and 23 references