We reviewed all cases of Nocardia infection in cystic fibrosis patients at 2 centers. Eight of 200 patients had Nocardia in sputum. Four developed severe lung disease, including 3 with associated allergic bronchopulmonary aspergillosis; 4 remained clinically stable. Nocardia is often associated with significant lung disease in cystic fibrosis, possibly associated with allergic bronchopulmonary aspergillosis or steroids.