The acute cardiovascular effects of smoking during stress may be greater than those of smoking or stress alone, a finding which could have implications for determining which smokers may be at particular risk for coronary heart disease (CHD). Methodological problems inherent in using tobacco smoking to deliver nicotine (believed responsible for smoking's cardiovascular effects) prevent clear examination of the cardiovascular effects of inhaled nicotine. This study compared the cardiovascular increases due to a video game stress task plus 1.0 mg nicotine with those of stress or nicotine alone using an aerosol method of presenting nicotine in measured doses. Twelve young male smokers each participated in four conditions on 4 separate days: stress+nicotine, stress+placebo (stress alone), rest+nicotine (nicotine alone), and rest +placebo. The effects of stress and nicotine were additive for heart rate but less than additive for systolic and diastolic blood pressure. These results indicate that the combined effects of stress and nicotine may be relevant to understanding the prevalence of CHD among smokers. They also suggest that the effects of each on cardiovascular activity may be different, as the effects are independent for heart rate but overlap for blood pressure.