Objective. To identify clinical signs that determine a phenotypic heterogeneity of idiopathic Parkinson's disease (PD) using cluster analysis. Material and methods. Cluster analysis was applied to main clinical signs characteristic of disease course and to the results of examination of 72 PD patients based on 5 scales. Results. Clinical signs that determine a phenotypic heterogeneity of PD were identified. The most significant variables were a form of disease, predominance of akinetic/rigid syndrome or tremor syndrome as well as the age at disease onset, severity of motor deficit and autonomic symptoms. Conclusion. The definition "a form of PD" has a wider meaning compared to established one. To determine a form of disease, we recommend to consider both the predominance of a definite motor symptom and a set of additional clinical parameters.