Changes in gross motor function during the intensive neurophysiological rehabilitation were studied in 61 patients, aged from 2 to 15 years, with spastic forms of cerebral palsy. All patients were examined before and at the end of a two-week course of treatment using the Gross Motor Function Measurement GMFM-66 Item Sets test to calculate motor development scores. Statistical analysis indicates a significant increase in the level of motor development of children after treatment from 45.1 to 47.6 (p > 0.01). The most significant progress was noted in patients at level II of Gross Motor Function Classification System. The score of motor development has increased from 66.2 to 69.6 (p < 0.01). The results suggest the effectiveness of the Intensive Neurophysiological Rehabilitation System for the improvement of gross motor functions in patients with cerebral palsy. It is necessary to continue this study according to the requirements of evidence-based medicine.