Abstract Background Workers are potentially exposed to asthmagens daily. Our study was conducted to estimate the prevalence of asthma among working adults in the U.S. by industry and occupation. Methods Using data from the National Health and Nutrition Examination Survey (2001–2004), multiple logistic regression was used to investigate associations between industry and occupation and current asthma as defined by positive responses to “Has a doctor or other health professional ever told you that you have asthma?” and “Do you still have asthma?” Results Workers in mining (17.0%), health‐related industries (12.5%), teaching (13.1%), or in health‐related occupations (12.6%) had the highest prevalence of asthma. As compared to construction industry workers, workers in mining (aOR = 5.2, 95% CI: 1.1–24.2) or health‐related (aOR = 2.3, 95% CI: 1.1–4.8) industries had significantly higher odds of asthma. Conclusion Our study adds to the increasing evidence that miners, healthcare workers and teachers remain high‐risk working populations and appropriate evaluation and control measures are needed to protect these workers. Am. J. Ind. Med. 53:463–475, 2010. © 2010 Wiley‐Liss, Inc.