Data came from a February 1994 survey of 402 Vietnamese students at two high schools located near the Vietnamese community in eastern New Orleans and at a public high school for honors students. Results revealed that involvement in the ethnic community has a strong negative effect on drug and alcohol abuse, both directly and indirectly, through lessening the likelihood that adolescents will have drug-abusing friends. Vietnamese language use was an especially influential aspect of ethnicity. Findings suggest that research on adolescent drug abuse should place more emphasis on community-level explanations, such as the effect of ethnic groups and other kinds of social groups that surround individuals and families. Tables and 16 references (Author abstract modified)