OBJECTIVE To investigate the effects of DL-3-n-butylphthalide (NBP) soft capsules combined with levodopa and benserazide (LB) on the motor function and serum homocysteine (Hcy) and insulin-like growth factor 1 (IGF-1) levels in elderly patients with Parkinson's disease (PD). METHODS One hundred elderly patients with mid to late-stage PD admitted to our hospital from March 2021 to March 2023 were included in this retrospective study and divided into control group (n=50) and observation group (n=50) based on different treatment methods. The control group received treatment with LB, while the observation group received treatment with LB and NBP soft capsules for a duration of 1 year. The clinical efficacy, Unified Parkinson's Disease Rating Scale (UPDRS) scores, Hoehn-Yahr stage, UPDRS-Ⅲ scores, serum Hcy levels, and IGF-1 levels before and after treatment were compared. RESULTS The clinical effect of the observation group was dramatically better than that of the control group (P<0.05). After 1 year of treatment, both groups showed significant reduction in UPDRS scores, Hoehn-Yahr stage, and UPDRS-Ⅲ scores compared to baseline. Furthermore, the observation group had dramatically lower UPDRS scores, Hoehn-Yahr stage, and UPDRS-Ⅲ scores compared to the control group (P<0.05). After 1 year of treatment, serum Hcy levels were dramatically lower in the observation group compared to the control group, while serum IGF-1 levels were dramatically higher (P<0.05). CONCLUSION In elderly patients with mid to late-stage PD, NBP soft capsules combined with LB can significantly reduce serum Hcy levels, increase IGF-1 levels, and improve motor function in patients with PD.