Smoking cessation treatment is an important prognostic factor for survival after a cancer diagnosis, especially for tobacco-related cancers. After being diagnosed with lung cancer, approximately 50% of patients continue smoking or frequently relapse after a quit attempt. Given the importance of smoking cessation treatment for cancer survivors, the objective was to compare the effectiveness of a 6-week intensive smoking cessation intervention, the Gold Standard Program (GSP), among cancer survivors compared with smokers without cancer. Second, we compared successful quitting among socioeconomically disadvantaged cancer survivors with that among nondisadvantaged cancer survivors.This was a cohort study based on 38,345 smokers from the Danish Smoking Cessation Database (2006-2016). Linkage to the National Patient Register was used to identify cancer survivors undergoing the GSP after being diagnosed with cancer (except nonmelanoma skin cancer). Linkage to the Danish Civil Registration System was used to identify participants who died, went missing, or emigrated before the follow-up. Logistic regression models were applied to evaluate effectiveness.Six percent (2438) of the included smokers were cancer survivors at the time they undertook the GSP. Their 6-month successful quitting showed no difference compared to that of smokers without cancer, neither before nor after adjustment; 35% versus 37% in crude rates and an aOR of 1.13 (95% CI: 0.97-1.32). Likewise, the results for disadvantaged compared to nondisadvantaged cancer survivors were not significantly different (32% versus 33% and an adjusted aOR of 0.87 (95% CI 0.69-1.11)). Overall, an intensive smoking cessation program seems effective in helping both people without cancer and cancer survivors become successful quitters.