['To determine the difference in the levels of nitrites in induced sputum of children with cystic fibrosis (CF) and controls. Furthermore, to evaluate the association between induced sputum nitrites and lung function in children with CF.', 'Nitrites, cell differentials, white blood cell count, were estimated in induced sputum of 20 children with CF and 10 age-matched healthy controls. Nitrites in induced sputum samples were measured using the Greiss assay. Lung function was ascertained by spirometry.', 'We observed high levels of nitrites in CF (184.8 +/- 11.07 microM/L) versus controls (56.4 +/- 5.7 microM/L) (p < 0.01). A positive correlation between neturophil percent and nitrites, white blood cell count and nitrites (p < 0.05) in children with CF was observed. Sputum nitrites correlated negatively with FEV(1) (p < 0.05) in children with CF.'] Do induced sputum nitrites correlate with FEV1 in children with cystic fibrosis?