Research suggests that fast life history strategy (LHS) may be a primary driver of substance use among young adults. However, a recent study reported that (a) young adult fast LHS did not subsume all theorized indicators of LHS during this period and (b) fast LHS among parents did not predict young adult fast LHS or liability for use of common substances. In this study, we used structural equations and national data to test whether these findings generalized to adolescence. In addition, given that LHS and substance use share genetic and neuropsychological bases, we examined whether fast LHS could explain the developmental stability of substance use. Overall, our results extend the findings discussed above and suggest that fast LHS fully explains the developmental stability of substance use among youth. We discuss implications for life history models, research applying life history theory and substance use, and substance abuse prevention and treatment.