Parkinson's disease (PD) patients are at a higher risk of malnutrition. The prevalence has been estimated to 0-24%, while 3%-60% of PD patients are reported to be at risk of malnutrition. To date, there is no clear explanation for malnutrition in these patients. The aim of this study was to determine the prevalence of malnutrition and to analyze factors that influence its appearance. The Mini Nutritional Assessment (MNA) was used to determine normal nutritional status; at risk of malnutrition; and already malnourished status. The Unified Parkinson's Disease Rating Scale (UPDRS) parts III and IV, Hoehn and Yahr scale (H&Y scale), Beck Depression Inventory (BDI), Mini Mental State Examination (MMSE), Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease-Rating Scale - eating part (QUIP-RS) and Mini Nutritional Assessment (MNA) were used to evaluate the factors affecting patient nutritional status. Out of 96 patients, 55,2% were at risk of malnutrition, while 8,3% had already been malnourished. Age, H&Y scale, UPDRS part III, 'off periods and depression influence negatively on MNA. More patients with 'off periods were rigor dominant. Thyroid gland hormone therapy was related to malnutrition, while patients with normal nutritional status used ropinirole more often than pramipexole. Factors affecting nutritional status are age, motor symptoms and stage severity, 'off states, rigidity dominant type with 'off states, and thyroid hormone replacement therapy. Ropinirole exhibited the possible 'protective' effect against malnutrition. (C) 2017 Elsevier B.V. All rights reserved.