Objective. Lateral amyotrophic sclerosis (LAS) is a very severe neurodegenerative disease with progressive course and terminal respiratory insufficiency. Non-invasive lung ventilation (NLV) is a main method of treatment. We studied the effectiveness of NLV in LAS and assessed patient's adaptation to NLV, life expectancy, compliance and an effect of NLV on spirometric parameters. Material and methods. NVL was administered to 28 patients, mean age 56.2±9.4 years, including 10 patients with bulbar onset and 16 with spinal onset. The rapid progression of the disease was observed in 15 patients, slow progression in 13 patients. Results and conclusion. NLV used in regime S extended the life of patients, in particular, patients with spinal onset. The adjustment to the NLV device plays a crucial role. Two types of the adjustment were established: gradual (13 patients) and accelerated (4 patients). The causes of the latter were not found. It should be emphasized that several questions related to the details of NVL regime should be specified in further research in the field.