We investigated the content of vascular endothelial growth factor (VEGF) in the blood plasma of patients suffering from the sporadic form of amyotrophic lateral sclerosis (ALS). Two groups of patients were selected for the study: in the first group, the disease started before the age of 40 and, in the second group, after the age of 40. In the older patients, the decrease in the content of VEGF correlated with the age and duration of the disease. This demonstrates the involvement of VEGF in the mechanisms of motor neuron death. In patients with early onset of ALS, the paradoxical reaction of VEGF under hypoxia conditions was revealed. This may be one of the mechanisms which determine the progression and severity of the disease in this group of patients. Our data on the impairment of VEGF regulation in the patients with sporadic form of ALS are the basis for the development of new methods of therapy with the use of neurotrophic factors.