Background: Numeracy is one's ability to use numbers in context and influence's decision making and perceptions of health risk. Worry about lung cancer is an indicator of perceived risk (PR) and is related to interest in cessation and cancer screening. Purpose: The analysis sought to explore underlying relationships among worry about lung cancer, smoking-related disease risk perceptions, and numeracy in a web-based panel. Methods: A Web-based survey, including a numeracy measure, was completed by 1,682 participants aged 18-65 recruited in 2014. Former and current smokers were asked about LC worry and current smokers were asked their PR of diseases associated with smoking. Results: Females (m = 25.64, 95% CI [24.67, 26.61]), respondents aged 45-65 (m = 26.15, 95% CI [24.89, 27.41]), those who worry "all the time" about LC (m = 27.62, 95% CI [25.66, 29.58]), and respondents perceiving a higher risk of LC compared to other smokers (m = 28.84, 95% CI [27.66, 30.01]) expressed significantly higher PR means. Higher household income (OR = 1.20, 95% CI [1.08, 1.34]), age (OR = 0.86, 95% CI [0.77, 0.98]), and comparative LC risk (OR = 2.52, 95% CI [2.01, 3.17]) were significantly associated with greater worry about LC. As PR increases by one unit, the probability of worrying increases by 4.6%. For numeracy scores, odds ratio showed that as scores increased by one unit, the probability of worrying decreased by 11.9%. Discussion: In this study, we have shown that PR has a positive association with LC worry and that numeracy has a negative association with LC worry. Translation to Health Education Practice: This information can be used to target subpopulations with low PR and numeracy about their risks for lung cancer and to develop tailored messages to educate these people. A "AJHE" Self-Study quiz is online for this article via the SHAPE America Online Institute (SAOI) http://portal.shapeamerica.org/trn-Webinars