OBJECTIVE To determine the prevalence of cigarette, alcohol and other drug use and associated factors of use among predominantly Caucasian small-city pregnant adolescents, a little-studied population. METHODS At the initial prenatal visit 117 enrollees completed a self-administered questionnaire. Patients provided urine samples for drug metabolites. Chart review determined medical provider documentation of substance use. RESULTS Thirty-five percent of patients were positive for alcohol or other drug use by questionnaire self-report, provider report or initial urine drug screening test. Thirteen percent of patients were positive for at least one drug metabolite in the urine. Multiple logistic regression analysis indicated a model with four significant risk factors associated with pregnant adolescent alcohol and other drug use: lack of closeness with the father of the baby, neither parent in the home, patient experiencing consequences of alcohol and other drug use, and father of the baby experiencing consequences of alcohol and other drug use. CONCLUSIONS The high prevalence of cigarette, alcohol and other drug use in this predominantly Caucasian sample was comparable to previous inner city data. Awareness of risk factors may improve identification and management of substance use among pregnant adolescents.