OBJECTIVES: Parkinson’s disease (PD) is the second most prevalent neurodegenerative disorder in the US. The Scales for Outcomes in Patients with Parkinson’s disease Diary Card (SCOPA-DC) is a daily diary designed to measure motor impairment in PD patients with fluctuating symptoms. Consistent with the FDA’s final guidance on patient-reported outcome measures, this study aimed to evaluate the content validity of the SCOPA-DC in the US and determine the feasibility of adding items that measure non-motor symptoms using qualitative techniques. METHODS: A literature review identified the most dominant non-motor symptoms experienced by PD patients with fluctuating symptoms. Three focus groups were conducted with PD patients (n=24) to identify themes that specifically addressed the study objectives. The original SCOPA-DC was modified based on findings from the literature review and patient input. A fourth focus group (n=9) consisted of a cognitive debriefing of the revised SCOPA-DC that included additional items and modified structure based upon the previous results. RESULTS: Findings from the focus groups demonstrated support for the content of the original SCOPA-DC, generally finding it to be clear and intuitive, despite difficulties with some item definitions, time frames, and response labels. With respect to non-motor symptoms, seven domains were consistently mentioned: fatigue, concentration/memory, anxiety, pain, difficulty swallowing, frequent urination, and sweating. The cognitive debriefing focus group reported that the revised SCOPA-DC format was easier to use, provided better focus on the items and time frames, and more adequately captured experiences throughout the day as compared to the original. CONCLUSIONS: Non-motor symptoms occur frequently in PD patients with fluctuating symptoms and have a significant impact on health-related quality of life. A reliable and validated patient-reported daily diary may improve the ability to describe PD progression by accurately measuring both motor and non-motor symptoms. Additional quantitative research is needed to evaluate the psychometric properties of the revised SCOPA-DC.