Introduction. Web-based interventions for smoking cessation are an innovative strategy to reduce the burden of smoking. Although many web-based interventions are freely available in many languages and have proven to be effective, so far no study has covered in detail the association between depression and smoking. Objective. The aim of this study was to evaluate the prevalence of depression among users of the Viva sem Tabaco, a web-based intervention for smoking cessation. Method. This was a retrospective cross-sectional study. In the internet-based intervention participated 1 433. Inclusion criteria were: being 18 years or older and a smoker; exclusion criteria were: omitting to fill out two questions of the screening depression questionnaire PHQ-2 and having made multiple accesses within a limited time span, characterizing invalid access. At the end, the sample had 461 participants. Participants answered questions related to sociodemographic characteristics, tobacco history, depression (PHQ-2 and PHQ-9), alcohol use, and intervention use. Results. Participants average age was 42.3 years (SD = 12.1). Most participants were female (67%), and 70% were employed during the time of the study. From the total sample, 36.4% of the participants presented depression according to PHQ-2. Being screened with depression was associated with tobacco dependence (OR = 1.10; 95% CI = 1.00, 1.20), and associated with not having a job (OR = .53; 95% CI = .29, .97). Discussion and conclusion. Depression may be a factor to be considered in programs that offer support to quit smoking through the internet for Portuguese Speakers.