<p>Tremor is one of the main motor symptoms of Parkinson’s disease, though its pathophysiology remains largely unknown. The research and clinical task is complicated by the clinical and pathomorphological heterogeneity of tremor and unpredictable responses to therapy. The characteristics of the degeneration of neurotransmitter systems responsible for the development of tremor and the effects of neurotransmitters on specific anatomical structures are considered in relation to existing models explaining tremor. The mechanisms by which changes in neurotransmitter systems can influence the clinical diversity of tremor and differences in response to therapy are discussed. Data from clinical studies demonstrating the effect of the dopamine receptor agonist piribedil on tremor are presented.</p>