Many hospital and residential chemical dependency treatment facilities utilize Alcoholics Anonymous (AA) and Narcotics Anonymous (NA) principles and practices in therapeutic programming. Although well-known and broadly endorsed and supported, such AA/NA approaches have received little research attention especially in regard to chemically dependent adolescents. The present study examined chemical usage and social-civil-productive functioning in 157 male and female chemically dependent adolescents at 6, 12 and 24 months after leaving an AA/NA-based treatment program. Results revealed that both treatment completers and noncompleters (those who left treatment prematurely against professional/medical advice) demonstrated less chemical use after their respective hospitalizations than before. Although significantly higher percentages of both male and female treatment completers were found abstinent/essentially abstinent at 6 months post discharge in contrast to noncompleters, abstinance rates, particularly for male subjects, declined sharply by 1 and 2 years after treatment. Results indicated that the AA/NA model is a promising approach in treating chemically dependent adolescents, but that much attention to relapse prevention methods is necessary.