The current study uses structural equation modeling to investigate factors associated with alcohol initiation and injection heroin use. Baseline data from the NEURO-HIV Epidemiologic Study in Baltimore, Maryland, were used. Participants were 404 injection heroin users (M(age) = 32.72) with a history of regular injection in their lifetime. Latent variables were created for self-reported school problems and academic failure. The final model indicated that greater school problems were associated with earlier alcohol initiation (ß = -0.22, p < .001) and earlier alcohol initiation was associated with greater frequency of recent heroin use (ß = -0.12, p < .05). Academic failure was directly related to greater frequency of recent heroin injection (ß = 0.15, p < .01). The results expand research investigating the relationship between adolescent behavior and illicit drug use in adulthood.