Alpha 1-antitrypsin deficiency is a relatively common genetic disease that is underrecognized and underdiagnosed. Early diagnosis in the asymptomatic patient helps modify lifestyle choices to reduce the risk of emphysema. In 2003, the American Thoracic Society and the European Respiratory Society issued guidelines to improve standards in diagnosing alpha(1)-antitrypsin deficiency. This review highlights key recommendations for diagnosis of alpha(1)-antitrypsin deficiency, including the different types of diagnostic tests recommended in the guidelines. Options for patient treatment will be discussed.