Impairment of swallowing is a common symptom in advanced stage of Parkinson's disease and severe defect of this function may cause aspiration pneumonia, problems with food intake and cachexy. The aim of this study was to assess the reflex and oral, pharyngeal, oesophageal phase of swallowing. Eleven patients with Parkinson's disease and 9 healthy subjects were investigated by electromyography (EMG) and oesophageal scintigraphy. The study demonstrates delayed triggering of swallowing reflex (543 +/- 84 ms in patients with PD vs. 230 +/- 66 ms in controls, p < 0.05) and prolongation of laryngeal movement (1880 +/- 140 ms vs. 1349 +/- 154 ms, p < 0.05). The prolongation of the oesophageal phase of swallowing with predilection to retention of water in lower one/third part of esophagus (12.45 +/- 2.45 s vs. 6.45 +/- 1.18 s, p < 0.001) was observed. The dysphagia limit, that is the maximum amount of water swallowed at once, was also evaluated (all normal subjects are able to swallow 20 ml water or more at once). In the studied patients with Parkinson's disease it was 4.5 +/- 0.86 ml. These results evidently and objectively indicate the presence of swallowing disorders in Parkinson's disease. Dysphagia was observed in all studied patients, although only 8 of them complained about it. In other 3 cases the impairment of swallowing was subclinical and it was connected with prolongation of oesophageal phase.