Clinical variants of Parkinson's disease (PD) are not restricted to motor symptoms but include a wide spectrum of different non-motor symptoms: cognitive, psychotic, autonomic and sensory. These non-motor symptoms often occur long before classical motor features. Associated pathologic changes can now be identified at earliest stages using neuroimaging, pathomorphological and genetic studies. Therefore, PD is currently considered as a multifactorial, heterogenic systemic disease associated with involvement of multiple neurotransmitter systems. This leads to understanding that not only dopaminergic but also other neurotransmitter systems, including glutamatergic system, are involved in the pathogenesis of PD. This article aimed at investigating a role of glutamatergic system in the initiation of neurodegenerative process. The role of glutamate as a neurotransmitter and a neurotoxin in the pathogenesis of PD and progression of its clinical manifestations is discussed. The authors suggest that research into glutamate excitotoxicity in PD patients might allow the improvement of treatment tactics and correction of pathogenetic therapy.