To study the possible impact of alcohol consumption on lung function (FEV1 and FVC), we observed 11,135 men and women for 5 yr. Subjects were between 20 and 90 yr of age and were selected so that they were representative of the population of the city of Copenhagen. The study population was stratified according to smoking habits and alcohol consumption. A total of 8,765 persons did not significantly change alcohol or smoking habits during the 5 yr of observation and constituted the study sample. The study sample included 32 women and 301 men with an alcohol consumption of greater than or equal to 350 g/wk (78 were nonsmokers). Multiple regression analysis showed that alcohol consumption significantly accelerated the loss of FEV1 and the loss of FVC with time. Consumption of 350 g of alcohol/wk had an effect on FEV1 comparable to the effect of smoking 15 g of tobacco/day.