Abstract. Objectives: To better understand conjoint smoking and drinking among young adult emergency department (ED) patients, the purposes of this investigation were: 1) to assess the prevalence of conjoint use; 2) to determine the factors associated with conjoint alcohol use and smoking; and 3) to address the implications for future ED-based investigation of dual-substance intervention. Methods: Data for this investigation were obtained from a battery of questionnaires administered to the routine-care patients during an alcohol screening in the ED, which was part of a larger alcohol intervention study. Results: Study findings revealed that a majority of patients with self-reported alcohol-related problems were smokers. In fact, drinkers who smoked were likely to be pack-a-day smokers. Among the study sample, being female, having low education levels (e.g., high school education or less), having some emotional problems, and currently using marijuana were risk factors for conjoint smoking and drinking. Conclusions: Conjoint users were identifiable through brief screening. Given the prevalence of conjoint smoking and alcohol use among the ED sample and a specific set of risk factors, tailored intervention for alcohol and nicotine dependence may be an important and opportunistic clinical ED service.