To explore the feasibility of using the Non-motor Symptoms Scale (NMSS) to assist in differentiating drug-induced parkinsonism (DIP) from Parkinson's disease (PD). Methods: A total of 21 patients with DIP (DIP group), 25 patients with PD who had not received medication treatment (PD group), and 22 patients without Parkinson's symptoms (control group) were selected from May 2023 to May 2024 in the Department of Neurology of our hospital. Clinical data of the patients were collected, and they were assessed using the Unified Parkinson's Disease Rating Scale Part III (UPDRS III) and the Hoehn and Yahr Staging Scale (H-Y). At the same time, the NMSS was used to evaluate the non-motor symptoms. The scale scores and their correlations among the three groups were compared and analyzed. Results: The scores of the NMSS in the DIP group and PD group showed significant differences compared with the control group. Except for perception (delusions of persecution, diplopia), attention and memory (difficulty remembering recent events, forgetting to do some things), gastrointestinal symptoms (dysphagia), and others (increased sweating), the differences in other items were statistically significant (P<0.05). Compared with the PD group, the scores of vascular symptoms, sleep and physical strength (daytime sleepiness, restless legs syndrome), attention and memory (inattentiveness), gastrointestinal symptoms (ptyalism), urinary symptoms, sexual function, and others (unexplained pain, alteration of taste and smell sense) in the DIP group were statistically significant (P<0.05). Spearman correlation analysis showed that the motor symptoms correlation (UPDRS III and H-Y) in the DIP group and PD group was low to moderately correlated (rs=－0.254, －0.519). Among other items, only sleep and physical strength (daytime sleepiness), attention and memory (inattentiveness), urinary symptoms, and others (alteration of taste and smell senses) in the DIP group were moderately correlated with those in the PD group (rs=0.370～0.497); sleep and physical strength (restless legs syndrome) was lowly correlated with the PD group (rs=0.279). No significant correlation was found in the remaining items (P>0.05). Conclusion: The NMSS score is helpful to improve the accuracy of differentiating early DIP from PD patients.