Objective: To review up-to-date economic outcomes data in patients with cystic fibrosis (CF), especially costs related to respiratory infection by Pseudomonas aeruginosa (Pa), the leading cause of morbidity and mortality in CF patients. Methods: A systematic search of the MEDLINE database from 1990-2007 was conducted, using the terms “cystic fibrosis” and “cost.” Selected conference abstracts were also searched. Recent articles that contained economic data on antibiotic and mucolytic therapies were selected for in-depth review. Results: In-depth review was performed on 27 articles that examined the economic impact of inhaled tobramycin (2 articles), the effect of home- vs. hospital-based antibiotic therapies for pulmonary exacerbations (4), economic impact of recombinant human deoxyribonuclease (rhDNase) (10), and cost-of-illness for CF (11). Inhaled tobramycin led to reductions in health care costs that offset 37%-57% of the drug cost. Home-based antibiotic therapy for exacerbations generally resulted in lower health care costs than hospital-based administration. Use of rhDNase led to reductions in health care costs that offset 17%-38% of the drug cost. Cost-of-illness studies have been conducted in 7 countries; the economic estimates varied widely ($9,000 to $64,000/patient/year; 2006 US dollars) due to differences in treatment patterns, health systems, methodologies, and subjects. Most cost-of-illness studies were retrospective observational studies of direct costs from the perspective of a hospital or third-party payer. The largest cost categories included hospitalizations, out-patient visits, rhDNase and antibiotics. Disease severity and Pa infection were major determinants of cost. Conclusion: Studies show that inhaled tobramycin and rhDNase partially offset medical costs; home-based antibiotic therapy likely reduces costs; and direct costs can be high but vary widely across countries and analytical methodologies. Areas for future research include direct comparisons of inhaled antibiotic therapies, examination of the relationship between treatment adherence and economic outcomes, and estimation of societal cost-of-illness.