BackgroundTobacco products differ in their relative health harms. The need for educating consumers about such harms is growing as different tobacco products enter the marketplace and as the FDA moves to regulate and educate the public about different products. However, little is known about the patterns of the public’s knowledge of relative harms.MethodsData were analyzed from the Health Information National Trends Survey (HINTS) 4 Cycle 2, a population-representative survey of US adults conducted between October 2012 and January 2013 (N = 3630). Participants reported their perceptions of the relative risks of e-cigarettes, smokeless tobacco, and different types of cigarettes compared to “traditional” cigarettes. Relative risk perceptions for each product type, as well as the consistency and accuracy of harm reduction beliefs, were analyzed.ResultsAbout 65 % of the respondents accurately reported that no cigarettes were less harmful than any others. Slightly more than half of US adults perceived e-cigarettes to be safer than regular cigarettes, a belief in line with current scientific evidence. By contrast, only 9 % of respondents perceived some smokeless tobacco products to be safer, a belief strongly supported by the evidence. Only 3.5 % of respondents had patterns of relative risk perceptions in line with current scientific evidence for all three modalities.ConclusionsThe discrepancy between current evidence and public perceptions of relative risk of various tobacco/nicotine products was marked; for most tobacco types, a large proportion of the population held inaccurate harm reduction beliefs. Although there was substantial awareness that no cigarettes were safer than any other cigarettes, there could be benefits from increasing the percentage of the public that appreciates this fact, especially among current smokers. Given the potential benefits of tobacco risk reduction strategies, public health education efforts to increase understanding of basic harm reduction principles are needed to address these misperceptions.