The present study examined the extent to which Marlboro Lights smokers perceive lower health risks associated with using a low-tar cigarette and the extent to which they are aware of filter vents in their cigarettes. The data for this study came from a nationally representative random-digit-dialed telephone survey of 1,046 adult current cigarette smokers (aged 18 years or older) conducted between May and September 2001. Respondents were asked about the brand and type of cigarettes smoked, beliefs about the health benefits associated with low-tar and filtered cigarettes, and awareness of ventilation holes in the filters of their cigarettes. Marlboro Lights was the most popular brand, smoked by 19% of survey respondents. Only 32% of Marlboro Lights smokers reported that the filters on their cigarettes were ventilated. Many Marlboro Lights smokers believed incorrectly that lower tar, light, and ultra-light cigarettes were less harmful compared with higher tar, full-flavored cigarettes. For example, only 11% of Marlboro Lights smokers knew that the tar delivery of a light cigarette was about the same as that of a full-flavored cigarette. The responses of Marlboro Lights smokers to questions about the hazards of low-tar cigarettes were similar to those expressed by smokers of other cigarette brands. The data presented in this paper reveal that smokers of the leading light cigarette brand sold in the United States today, Marlboro Lights, are for the most part unaware of filter vents in the cigarettes they smoke and are misinformed about the health risk of using low-tar and filtered cigarettes.