OBJECTIVE: We examined whether amantadine can prevent the development of dyskinesia. METHODS: Patients with drug-naïve Parkinson's disease (PD), younger than 70 years of age and in the early stage of PD (Hoehn and Yahr scale < 3), were recruited from April 2011 to December 2014. The exclusion criteria included the previous use of antiparkinsonian medication, the presence of dyskinesia, significant psychological disorders, and previous history of a hypersensitivity reaction. Patients were consecutively assigned to one of 3 treatment groups in an open label fashion: Group A-1, amantadine first and then levodopa when needed; Group A-2, amantadine first, dopamine agonist when needed, and then levodopa; and Group B, dopamine agonist first and then levodopa when needed. The primary endpoint was the development of dyskinesia, which was analyzed by the Kaplan-Meier survival rate. RESULTS: = 0.453). CONCLUSION: Amantadine as an initial treatment may decrease the incidence of dyskinesia in patients with drug-naïve PD.