In order to investigate the sleep quality and influencing factors in patients with Parkinson's disease (PD), 201 PD patients were enrolled and underwent extensive clinical evaluations. Subjective sleep evaluation was assessed using the Pittsburgh Sleep Quality Index (PSQI), and the Epworth Sleepiness Scale (ESS). It was found that poor sleep quality (77.11%) and excessive daytime sleepiness (32.34%) were commonly seen in PD patients and positively correlated with disease severity. Then 70 out of the 201 PD patients and 70 age- and sex-matched controls underwent a polysomnographic recording. The parameters were compared between PD group and control group and the influencing factors of sleep in PD patients were analyzed. The results showed that sleep efficiency (SE) was significantly decreased (P < 0.01), and sleep latency (SL) and the arousal index (AI) were increased (P < 0.05) in the PD group as compared with those in the control group. SE and total sleep time (TST) were positively correlated with the Hoehn and Yahr (H&Y) stage. There was significant difference in the extent of hypopnea and hypoxemia between the PD group and the control group (P < 0.05). Our results indicate that PD patients have an overall poor sleep quality and a high prevalence of sleep disorder, which may be correlated with the disease severity. Respiratory function and oxygen supply are also affected to a certain degree in PD patients.