This report presents results from the 2016 National Survey on Drug Use and Health (NSDUH) for people aged 12 or older regarding the perceived harmfulness of using cigarettes, alcohol, and specific illicit drugs as well as the perceived availability of substances. Estimates are presented for specific age groups. Estimates of the perceived great risk of harm associated with the use of marijuana, cocaine, alcohol, and cigarettes also are presented according to whether people initiated use of these substances in the past year.