The present study tested the hypothesis that limited ability to tolerate physical and psychological distress is associated with early relapse from smoking cessation. Specifically, the authors exposed 16 current smokers who had failed to sustain any previous quit attempt for more than 24 hr (immediate relapsers) and 16 smokers with at least 1 sustained quit attempt of 3 months or longer (delayed relapsers) to psychological (mental arithmetic) and physical (carbon dioxide inhalation-breath holding) stressors. Relative to delayed relapsers, immediate relapsers were characterized by higher baseline levels of affective vulnerability, by greater levels of dysphoria and urge to smoke after 12 hr of nicotine deprivation, and by less task persistence on the stressors, suggesting that these may be risk factors for early lapse in the context of quitting smoking.