Non-invasive lung ventilation with a BiPAP respirator was given for 16 patients with an acute pulmonary insufficiency against the chronicle obstructive lung disease background. The aim was to investigate a possibility of the non-invasive pulmonary ventilation therapy as well as its advantages and disadvantages. When admitted to a hospital all patients had gas exchange disorder (Pa02 was 53.9±18.3 mm Hg, PaC02 — 61.0±12.2 mm Hg and pH — 7.28±0.09) together with the respiratory mechanics failure (FEV1>1 I). The non-invasive lung ventilation therapy was efficient for 13 of 16 patients (3 patients refused as they badly endured mask ventilation). The average ventilation time was 13 hours a day for 2.5 days. Complications were rare and required no ventilation canceling. In the group of patients refused the non-invasive lung ventilation one patient died of septic shock after intubation and subsequent invasive pulmonary ventilation, one patient died of a gastrointestinal hemorrhage and one more patient was discharged from the hospital after the acute pulmonary insufficiency resolution. The gas exchange parameters began to improve in an hour after starting noninvasive lung ventilation: pH increased up to 7.36±0.11, Pa02 up to 80.1 ±17.7, Pa02/Fi02 up to 289.7±40.00 and PaC02 decreased to 48.7±9.2 mm Hg. Thus patients with an acute pulmonary insufficiency against a chronic obstructive lung disease background are successfully cured due to noninvasive lung ventilation.