Objective: Graphic warning labels (GWLs) are effective in communicating tobacco-related harms. Methods: In this mixed-methods study, we used purposive sampling to recruit 100 low-income smokers in the San Francisco Bay Area between October 2017 and February 2018 to participate in an intervention promoting smoke-free homes. We presented the 2009 Food and Drug Administration-proposed GWLs and explored perceptions of affect, efficacy, and appeal using questionnaires at baseline, 3- and 6-months follow-up. Because of participants' interest in this topic, we subsequently conducted a qualitative sub-study among 20 participants exploring perceived efficacy of GWLs on smoking cessation. Results: In all, 87.3% and 59.2% agreed that GWLs were useful and would motivate cessation behaviors, respectively, at baseline. We found that the most common responses were shock (61.8%) and disgust (55.3%), whereas anger (29.0%) and annoyance (19.7%) were less common. Participants also reported that GWLs unequivocally illustrating smoking's harmful effects were more appealing than non-specific images, as were images that depicted positive cessation-related effects. Conclusions: GWLs appear to be an important health communication among low-income smokers. Future studies on GWLs should examine the association of negative affect and cessation among this population.