Objective To explore the neuroprotective effect and mechanism of fisetin on Parkinson's disease (PD).Methods A subacute PD mouse model was established by intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). The mice were randomly divided into three groups: control, MPTP, and fisetin+MPTP, with five mice in each group. Mouse behavior was assessed by open field test, pole test, and wire hanging test. Western blotting and immunofluorescence were used to measure the expression of TH protein in the striatum and the number of TH-positive neurons in the substantia nigra. Nissl staining was used to detect neuronal damage in the substantia nigra. The level of oxidative stress in brain tissue was evaluated by measuring glutathione (GSH), superoxide dismutase (SOD), total antioxidant capacity (T-AOC), and malondialdehyde (MDA) in the striatum.Results Fisetin attenuated the MPTP-induced decreases in total distance traveled and mean velocity (P<0.05). Moreover, compared with the control group, MPTP increased the total time and turn time in pole test, which were alleviated by fisetin treatment (P<0.05). In wire hanging test, fisetin increased the score of mice compared with the MPTP group (P<0.05). Nissl staining showed that fisetin could ameliorate the neuronal damage in the substantia nigra of MPTP mice (P<0.05). Western blot and immunofluorescence showed that fisetin could alleviate the decrease in TH expression and the loss of positive neurons induced by MPTP (P<0.05). Treatment with fisetin increased the levels of GSH, SOD, and T-AOC in MPTP mice, but decreased the content of MDA in the striatum of MPTP mice (P<0.05).Conclusions Fisetin can significantly improve the motor function of MPTP-induced PD model mice and ameliorate the dopaminergic neuronal damage in the substantia nigra-striatum, and the underlying mechanism might be closely related to the antioxidant effect of fisetin.