OBJECTIVE: This study examines the effects of alcohol, tobacco and drug use on the quality of life of teenage mothers with infants. With a pregnancy rate of 30.4:1000 for the US population and 26.3:1000 for Oregon, a threatened quality of life is faced by thousands of young women in America. METHOD: A randomized controlled study of in-home counseling using a readiness to change model and motivational interviewing (n=154) was compared to standard services (n=132). Data were collected at baseline, 6, 12 and 18-month follow-ups. Differences are considered for tobacco, alcohol and marijuana use, quality of life and risk and protective factors. There were two social-environmental risk factors (neighborhood stress and perceived safety) and two protective factors (peer support and adult support); there were two personal risk factors (impulsiveness and depression) and two protective factors (self-efficacy and physical health). RESULTS: QOL showed some improvement over the course of treatment, although the association between QOL and dose of services was mixed. Baseline QOL was correlated with current marijuana use (-.13, p < .05) and use at the 6-month follow-up (-.16, p < .05). There were no associations with the 12 and 18-month follow-up visits. Alcohol use was associated with lower QOL at baseline, but not at the follow-up assessments. Of the eight risk and protective factors, QOL was predicted by self-efficacy, physical health, and mental well-being, i.e., Y = 3.41 + [(.36 * efficacy) + (.17 * health) + -.21 * depression)]. CONCLUSIONS: These results suggest that substance use does not have a strong adverse impact on QOL as young women with infants reach the age of majority. The results suggest that a means for promoting QOL be by enhancing self-competency, improving one's health and treating depression. The results are discussed in terms of America's neo-prohibitionist "war on drugs" policy.