Refinements in standard therapy for cystic fibrosis have led to dramatic increases in survival and quality of life over the past three decades. Standard therapy has consisted of oral and intravenous antibiotics, chest percussion with postural drainage, and aerosol bronchodilator therapy. The discovery of the cystic fibrosis gene and elucidation of the underlying biochemical defect have broadened our understanding of the pathophysiology of cystic fibrosis and provided a rationale for many new and innovative therapies. Modulation of airway epithelial ion transport may improve mucociliary clearance and delay colonization by infective organisms. Anti-inflammatory therapy may decrease lung injury that results from the host's attempt to limit airway infection. Supplementation of airway antiproteases may limit the destructive effects of unopposed proteases on pulmonary architecture. Genetic biotechnology has already produced agents that preserve pulmonary function and decrease infectious exacerbations by altering the viscoelastic properties of sputum from patients with cystic fibrosis. Both active and passive immunotherapy are currently being investigated as a measure to delay or combat endobronchial infection with Pseudomonas spp. Aerosolized aminoglycoside antibiotics are being increasingly employed to control pulmonary infection while minimizing systemic toxicity. These treatment modalities, combined with the prospects for gene therapy, provide a brighter outlook for the patient with cystic fibrosis than ever before.