There are data to suggest a relationship between alcohol consumption, particularly beer, and lung cancer. This hypothesis was tested on data from a cohort of 41,837 Iowa women aged 55 to 69 years. Women were recruited by mail and provided information on alcohol and tobacco use, physical activity, and education. Compared to a randomly selected group of women without lung cancer (n = 1900), those with lung cancer (n = 109) consumed more alcohol (measured on the Willett food frequency questionnaire) (10.2 versus 3.6 g/d; P = 0.001). The difference was accounted for largely by differences in beer consumption (3.5 versus 0.6 glass/wk; P = 0.003). Liquor consumption by patients was about double that by control subjects (1.7 versus 0.8 glass/wk; P = 0.063). Wine consumption was low and did not differ between those with and those without lung cancer. The relationship between beer consumption and lung cancer risk appeared U-shaped. After adjusting for the other variables (including six categories of pack-years of smoking), beer consumption remained a significant predictor of lung cancer risk. Those drinking 1 or more beers per week had an odds ratio of 2.0 (95% confidence interval, 1.02 to 3.80) compared with those consuming less than 1 glass per week. There was no evidence of interaction with smoking. The association of beer with lung cancer does not appear to be explained solely by confounding with cigarette smoking, although that remains by far the single strongest predictor of risk.