Introduction: Smoking denormalization has been paralleled by reduced smoking prevalence, but smoking rates among socioeconomically disadvantaged populations remain high. The social unacceptability of smoking has also led to increased perceptions of smoking-related stigma. By examining how smoking stigma influences cessation intervention effectiveness, we can better tailor interventions to socioeconomically disadvantaged smokers. Aims and Methods: Data are from a randomized controlled trial evaluating the effectiveness of a proactive cessation intervention on abstinence. Current smokers enrolled in Minnesota Health Care Programs were randomized to proactive outreach (n = 1200) or usual care (n = 1206). The intervention included mailings, telephone outreach, counseling, and access to free cessation treatments. Using baseline measurements, groups with lower (n = 1227) and higher (n = 1093) perceived stigma were formed. Intervention, stigma, and their interaction term were added to a logistic regression modeling abstinence at 12 months. Results: Lower perceived smoking-related stigma was associated with less support for quitting, lower rates of physician quitting advice, and less motivation for quitting. A logistic regression modeling abstinence found a significant intervention × stigma interaction. The proactive intervention was more effective among smokers with lower perceived smoking-related stigma (odds ratio 1.94, 95% confidence interval, 1.29 to 2.92) than those with higher perceived smoking-related stigma (odds ratio 1.04, 95% confidence interval, 0.70 to 1.55). Discussion: Smokers with lower perceived smoking-related stigma had social environments that were conducive to smoking, received less physician advice to quit, and were less motivated to quit than higher stigma smokers. Despite these barriers, the intervention was more effective for lower stigma smokers, suggesting that proactive outreach is an efficient treatment for these hardto-reach smokers. Implications: Smoking denormalization has led to increased perceptions of smoking-related stigma among many smokers; however, little is known about how this stigma influences the cessation process. In the present study, smokers with lower levels of perceived smoking-related stigma lived in social environments that were more conducive to smoking and were less motivated to quit than higher stigma smokers. Despite these barriers, our proactive outreach cessation intervention was more effective for lower stigma smokers, suggesting that interventions which utilize proactive outreach to stimulate interest in quitting and offer facilitated access to free cessation treatments are an effective treatment approach for these hard-to-reach smokers. These strategies may be particularly effective for motivating smokers enrolled in government-subsidized health insurance programs to take advantage of cessation resources.