An error has occured in the exclusions to obtain the final analytic sample for the research paper titled "Smoke-free laws and secondhand smoke exposure in US nonsmoking adults, 1999-2002" which was published in the August 2006 issue of Tobacco Control. The authors inadvertently did not excude 51 persons who indicated that they had used tobacco products in the past 5 days from the 2001-2002 NHANES survey because of a slight modification in the variable name from the 1999-2000 survey. If the exclusion had been applied correctly the final analytic sample would have consisted of 5815 persons rather the 5856, a difference of less than 1 percent. The authors have not yet rerun their analyses with the correct exclusion, but do not expect any substantial differences in their results or conclusions because the difference in the sample size is so small.