The study found that a link between sexual orientation and substance use behavior among AAPIs did not emerge until young adulthood. Among young adult sexual minority AAPIs, there were significant increases in the incidence and prevalence of all four types of substance use (tobacco, binge drinking, marijuana, and other drugs). Specifically, being an AAPI sexual minority young adult woman was significantly associated with such substance use compared with being a heterosexual young woman, a heterosexual young man, or a sexual minority young man, after controlling for demographic characteristics, problem behaviors, and substance use during adolescence. These findings show the urgency of drug abuse prevention and treatment programs that target sexual minority young adult AAPIs, particularly women. Future research should examine the influence of sociocultural factors in substance use specific to AAPIs. Study data were obtained from the National Longitudinal Study of Adolescent Health, Wave II (1996) and Wave III (2001), with the focus on a nationally representative sample of 1,108 AAPIs from both Waves, which indicated substance abuse changes from adolescence into young adulthood. Weighted prevalence, incidence, and patterns of smoking, binge drinking, marijuana use, and other drug use were analyzed by sexual orientation and gender. Multiple logistic regression analyses were conducted in order to determine the distinctive influence of being a sexual minority in relation to the four types of substance use by gender. 4 tables and 39 references