Background Ps.aeruginosa pulmonary infection in children with cystic fibrosis (CF) is a major problem with negative impact on the evolution of disease and quality of life in these patients.

Aim Elucidate the efficacy of the inhalation therapy with Colistin in children with CF and Ps.aeruginosa pulmonary infection.

Methods The study included 15 children with CF and Ps. aeruginosa pulmonary infection aged 1.5 to 4-year, who underwent bacteriological examination of bronchial secretion before and after treatment with titration diagnosis of germ.

Results In the step of including in inhalation therapy with Colistimethate sodium 13 children (86.6%) had BMI 14.48 ± 0.15, which during 1–1.5 years increased significantly to 16.32 ± 0.2 (p < 0.036). All children included in the study suffered from pulmonary infection with Ps. aeruginosa diagnostic titer from 10⁸ to 10³ micr/ ml. After the treatment with Colistin the infection was eradicated in 6 children (40%), in 8 children (53.3%) the concentration decreased up to 10⁵–10³ micr /ml and in only one case the titer of Ps.aeruginosa bronchial secretions remained unchanged (10⁴ micr/ml).

Conclusion Antibacterial inhalator therapy with Colistimethate sodium in infants with CF, affected by Ps.aeruginosa pulmonary infection, produces beneficial effects on the nutritional status of children, offers high chance (40%) eradication of this infection and improves the prognosis of the disease.