Incense burning, a source of household indoor air pollution, is possible to effect on cardiovascular system. Our study sought to examine the association of long-term exposure to household incense smoke with increased carotid intima-media thickness (CIMT). A cross-sectional study was conducted 132 adults aged ≥35 years. Participants were stratified into 3 groups by their long-term household incense use; nonexposed group, non-daily exposed group, and daily exposed group. A combined mean CIMT (mean difference = 0.04 mm; P < .01) and combined maximum CIMT (mean difference = 0.09 mm; P < .01) in the daily exposed group had greater than the nonexposed group. The mean CIMT and maximum CIMT of the left common carotid artery in the daily exposed group was significantly greater than the nonexposed group ( P < .01). These findings suggest that incense burning inside the house may be a risk factor for cardiovascular disease morbidity and mortality.