Dopamine replacement therapy reduces most motor and nonmotor features of Parkinson's disease. However, with disease progression, adjustments of dopaminergics and the application of advanced therapies must be considered.To validate the OPTIMIPARK questionnaire as a tool to help clinicians make therapeutic decisions on patients treated with levodopa.We tested a questionnaire including 9 items encompassing motor and nonmotor signs, complications, and disability in a multicenter, observational, cross-sectional study. A neurologist (neurologist 1 [N1]) assessed patients according to regular clinical practice and blinded to the OPTIMIPARK questionnaire score. Therapeutic decisions were classified as "no changes," "adjustment of conventional treatment," and "advanced therapy indicated." External neurologists (neurologist 3 [N3] and neurologist 4 [N4]), who only knew the patient age, years of disease, and current treatment, made their therapeutic decisions based on the OPTIMIPARK score. Concordance between the criterion of the N1 versus the OPTIMIPARK-based N3-N4 consensus was analyzed applying weighted κ. The area under Receiving Operating Characteristic (ROC) curves was calculated for OPTIMIPARK scores.A total of 113 patients with Parkinson's disease were included. The OPTIMIPARK-based decision led to a higher proportion of patients requiring therapeutic modification than N1 assessment (74% vs. 60%;OPTIMIPARK might be more sensitive than regular clinical practice in suggesting the need for a therapeutic change. Furthermore, the low and high scores identify with high accuracy well-adjusted patients and candidates for advanced therapy, respectively.