Purpose: To determine the effect of a combination of ginkgo leaf tablets with compound carbidopa tablets on cognitive function, serum homocysteine (Hcy), malondialdehyde (MDA) and neuron-specific enolase (NSE) levels in patients with Parkinson's disease (PD).Methods: A total of eighty (80) PD patients admitted to The Affiliated Hospital of Xuzhou Medical University, Xuzhou, China between December 2020 and December 2022 were randomly divided into two groups: Western medicine group (n = 40, using compound carbidopa tablets alone) and combination group (n = 40, using ginkgo leaf tablets combined with compound carbidopa tablets), and orally treated for 3 months. Mini-mental state examination (MMSE) and Montreal Cognitive Assessment (MoCA) were used to assess cognitive function before and after treatment. High-performance liquid chromatography was used to determine serum Hcy levels, while enzyme-linked immunosorbent assay (ELISA) was used to evaluate serum MDA and NSE levels. Adverse reactions were also recorded during treatment.Results: Total response rate following treatment in combination group was significantly higher than in Western medicine group (95.00 vs 80.00 %, p < 0.05). After treatment, MMSE and MoCA scores in combination group were significantly higher (p < 0.05) than those in Western medicine group, while serum Hcy, MDA and NSE levels in combination group were significantly lower than those in Western medicine group (p < 0.05). During treatment, there was no significant difference in incidence of adverse reactions between the two groups (p > 0.05).Conclusion: Ginkgo leaf tablets in combination with carbidopa significantly improve cognitive functions associated with PD with high safety, when compared to carbidopa tablets alone. However, further clinical trials are commended to validate these findings.