Influence of the dominant hemisphere on the clinical presentation of Parkinson's disease Objectives: To examine whether there is a difference in the incidence and severity of motor and non-motor symptoms depending on the dominantly affected side. Study design: Cross-sectional study. Subjects and methods: The study included patients treated at the Clinic for Neurology of the KBC Osijek. Patient data was collected from medical records and from the completed UPDRS III, NMS quest and SCOPA-AUT questionnaires that we used for the purposes of this research. Results: 46 patients with idiopathic Parkinson's disease participated in the study, of which 37 % were women and 63 % were men, median age 68 years. Of the total number of patients, 76.1 % had a dominantly affected right side, while 23.9 % of them had a dominantly affected left side of the body. Patients with a dominantly affected left side of the body often have more non-motor symptoms, but after correction for age, sex and duration of the disease, there was not observe a statistically significant difference. The results showed an increased frequency of weight loss, dysphagia, and restless legs syndrome in patients with dominantly affected left side. No difference was observed in the severity of motor symptoms, disease stage or autonomic symptoms between the examined groups. Conclusion: Patients with a dominantly affected left side of the body more often have symptoms of dysphagia, weight loss and restless legs syndrome