["Electrophysiological methods could provide important information about the neurophysiological status in Parkinson's disease (PD).", 'To investigate the prolonged auditory P300 latency in PD and its association with the disease clinical stage.', 'Clinical profiles of 44 patients were evaluated and those in initial and advanced stages of PD were identified. The frequency of altered latencies, median of latencies in each stage, and correlation between latencies and motor and non-motor clinical features were analyzed. Latencies were considered altered when they were more than two standard deviations from the mean of controls, per age group.', 'It was verified 10% of alterations in initial stages and 31% in advanced. There was correlation between latencies and non-motor clinical features. Subjects older than 65, in advanced stages, presented a significant increase of latencies.'] Are delayed latencies of auditory evoked potential P300 associated with the severity of Parkinson 's disease in older patients?