The authors examined gang activities in three major cities: San Francisco, including Oakland and San Jose; southern California, encompassing Los Angeles and Orange counties; and New York City, including the boroughs of Manhattan, Queens, and Brooklyn. They interviewed more than 200 police officials and community leaders over a 2-year period. Field notes, official reports and documents, journal articles, and media sources provided data about the dimensions of all forms of crime within the Asian communities in the study sites. In providing modified explanations on the causes of the emergence of Asian youth gangs, the authors advise that the conventional emphasis on social disorganization and the immigrant gang subculture (Sutherland, 1939; Cohen, 1955; Chin, 1990) has weak application to the unique social milieu of the Asian immigrant youth. In addition to ethnicity and region, this study found that the structure of youth gangs must be considered when examining causes for their origin and continued existence. Various Asian groups yield different kinds of youth gangs largely due to the kind of adult racketeering within the ethnic community. The authors contend that community disorganization caused by weak control by families, schools, and other institutions, as well as the internalization of criminal subcultural values are necessary but not sufficient factors in explaining the formation of Asian youth gangs in the United States. Failure of Asian immigrant youth to cope satisfactorily with issues of identity and their reaction to law enforcement tactics must be included in causal models that consider Asian youth gangs as supplements to matters of ethnicity, region, and gang structure. 2 figures and 32 references