BACKGROUND: While primary care medical clinics have been the most common setting for the delivery of advice about smoking cessation, the hospital emergency department (ED) is a valuable context for counseling medically underserved tobacco users. We conducted a secondary analysis based on a larger audio-recorded study of patient-provider communication about pain and analgesics in the ED. Within a sample of ED patients with back pain, the purpose of this mixed-methods study was to examine how physicians and nurse practitioners capitalize on “teachable moments” for health education to offer spontaneous smoking cessation counseling in the ED. METHODS: Patients presenting to an academic ED with a primary complaint of back pain were invited to participate in a study of patient-provider communication. Audio-recorded encounters were transcribed verbatim. Two coders reviewed each transcript to determine whether smoking was discussed and to build a corpus of smoking-related discussions. We then developed inductively generated coding categories to characterize how providers responded when patients endorsed smoking behavior. Categories were refined iteratively to accommodate discrepancies. RESULTS: Of 52 patient-provider encounters during which smoking was discussed, two-thirds of the patients indicated that they were smokers. Providers missed opportunities for smoking cessation counseling 70% of the time. Eleven encounters contained teachable moments for smoking cessation. We identified four primary strategies for creating teachable moments: 1) positive reinforcement, 2) encouragement, 3) assessing readiness, and 4) offering concrete motivating reasons. CONCLUSIONS: Most providers missed opportunities to offer teachable moments for smoking cessation. In encounters that contained teachable moments, providers employed multiple strategies, combining general advice with motivation tailored to the patient’s particular circumstances. Creating motivational links to enhance smoking cessation efforts may be possible with a minimal investment of ED resources.