BACKGROUND: Alpha-1 antitrypsin deficiency is a genetic disorder that leads to early-onset emphysema. Recently, exogenous supplementation of the enzyme has become a therapeutic alternative. OBJECTIVE: To review the role of so-called augmentation therapy with pooled human plasma alpha-1 antitrypsin as a specific treatment for emphysema caused by alpha-1 antitrypsin deficiency. METHODS: The authors performed a Medline (1966 - 2007) search with the keywords 'alpha-1 antitrypsin deficiency' and 'therapy'. The authors focused on articles regarding biochemical and clinical efficacy. RESULTS/CONCLUSION: Augmentation therapy has been shown to raise antiprotease serum and epithelial lining fluid levels above the 'protective threshold' value. Evidence suggests that this approach slows the decline in lung function, could reduce infection rates, might enhance survival, and is well tolerated. Questions about the cost-effectiveness of this therapy remain.