We conducted a randomized trial of parents and their 9- to 16-year-old children to pilot test an emergency department (ED)-based intervention designed to increase parent-child tobacco communication. Intervention group (IG) parents received verbal/written instructions on how to relay anti-tobacco messages to their children; control group (CG) parents received no specific instructions. Of the 540 subjects, 268 (49.6%) were randomized to the IG; both groups were similar at baseline. At one-month follow-up, IG children were more likely to report that they would definitely not smoke in the next 6 months (96.3% and 88.4%, p = 0.01), that there were an increased number of: child-initiated tobacco conversations (F(1,386) = 5.7, p = 0.02), times parents talked to them about: refusing cigarettes (F(1,380) = 7.6, p = 0.006), and reasons not to smoke (F(1,377) = 6.0, p = 0.015). Our pilot study has shown increases in parent-child tobacco communication after an ED-based intervention, suggesting that the ED may be an appropriate setting to encourage parent-child tobacco communication.