According to the National Institute of Diabetes and Digestive and Kidney Diseases, between 30 and 50 million Americans have the potential for lactose-intolerance symptoms. However, lactose-intolerance prevalence rates in practical life settings may be lower than originally suggested. The goal of this study was to determine the prevalence of self-reported lactose intolerance among a national sample of European American (EA), African American (AA), and Hispanic American (HA) adults. A nationally representative sample of randomly generated telephone numbers was purchased from a commercial sample provider. A nationally representative sample of randomly selected telephone numbers were called from the Survey Research Unit's Computer-Assisted Telephone Interviewing facility at the University of Alabama at Birmingham. Interviews were completed by a total of 1,084 respondents between the ages of 19 and 70 years with 486 EAs, 355 AAs, and 243 HAs. The response rate was 24.2%, and the cooperation rate was 34.2%. The age-adjusted lactose-intolerance prevalence estimates were 7.72%, 19.50%, and 10.05% for EAs, AAs, and HAs, respectively. For all respondents in the sample, the crude and age-adjusted self-reported lactose-intolerance prevalence rates were 13.38% and 12.04%, respectively. These results indicate that the prevalence of perceived lactose intolerance is significantly lower than what has been previously estimated. Health professionals need to be aware of the misrepresentation of currently estimated lactose-intolerance rates and should continue to encourage individuals with lactose intolerance to consume dairy foods first to help meet key nutrient recommendations with proper guidance and education Copyright © 2009 Lippincott Williams & Wilkins.