Objective To investigate the efficacy of pramipexole hydrochloride combined with Madopar in the treatment of Parkinson’s disease (PD) and its impacts on P100 latency of visual evoked potential (VEP).Methods Sixty patients with PD who were admitted to our hospital from March 2014 to April 2016 were divided into control group (n=28) and observation group (n=32). The control group was treated with Madopar for 12 weeks, while the observation group was given Madopar combined with pramipexole hydrochloride for 12 weeks. PD Rating Scale Part III (UPDRS III) was used to score the two groups before and after treatment. Treatment outcomes were compared between the two groups. P100 latency was evaluated by VEP examinations before treatment and after 12 weeks of treatment.Results The marked and overall response rates were significantly higher in the observation group than in the control group (71.88% vs. 39.29%, P < 0.05; 90.63% vs. 64.29%, P < 0.01). After 12 weeks of treatment, the observation group had a significantly lower UPDRS score than the control group (16.14±10.12 vs. 24.21±12.12, P<0.05). Both groups had substantially prolonged P100 latency before treatment. However, there was no significant difference between the two groups (P>0.05). After 12 weeks of treatment, the observation group had a significantly reduced P100 latency (P<0.05), while there was no significant difference in P100 latency before and after treatment in the control group.Conclusions Pramipexole hydrochloride combined with Madopar can significantly improve patients' motor symptoms and shorten P100 latency in the treatment of Parkinson’s disease.