Prognosis for patients with cystic fibrosis has improved dramatically over the past three decades. In the United States, median survival age is now 28.9 years. Although genotype predicts exocrine pancreatic function, it does not correlate with pulmonary status or overall clinical outcome. However, there are a number of parameters, such as exocrine pancreatic sufficiency, male gender, absence of colonization with mucoid Pseudomonas aeruginosa, presentation with predominantly gastrointestinal symptoms, balanced family functioning and coping, and compliance with treatment regimens, that predict a more favorable outcome. The impact of early diagnosis and treatment is still controversial. Although nonblinded studies indicate decreased morbidity in the first 2 to 4 years of life among patients diagnosed by newborn screening, no data support long-term benefit in terms of pulmonary function or survival. With increased longevity, there is now evidence of a small but significantly increased risk of gastrointestinal tract cancer among patients with cystic fibrosis.