We sought to understand smokers' perceived likelihood of health problems from using cigarettes and four non-cigarette tobacco products (NCTPs: e-cigarettes, snus, dissolvable tobacco, and smokeless tobacco). A US national sample of 6,607 adult smokers completed an online survey in March 2013. Participants viewed e-cigarette use as less likely to cause lung cancer, oral cancer, or heart disease compared to smoking regular cigarettes (all p < .001). This finding was robust for all demographic groups. Participants viewed using NCTPs other than e-cigarettes as more likely to cause oral cancer than smoking cigarettes but less likely to cause lung cancer. The dramatic increase in e-cigarette use may be due in part to the belief that they are less risky to use than cigarettes, unlike the other NCTPs. Future research should examine trajectories in perceived likelihood of harm from e-cigarette use and whether they affect regular and electronic cigarette use.