Objective: Individuals with Parkinson’s disease (PD) can have difficulties with activities of daily living (ADL) that stem from cognitive, motor, or affective manifestations of the disease. Accurately attributing ADL difficulty specifically to cognitive decline is critical when conducting a neuropsychological evaluation of a person with PD. Informant description of ADL performance is frequently used for this purpose, but there has been little work assessing informants’ ability to attribute ADL dysfunction to a specific symptom source in PD. Method: Fifty community dwelling individuals with PD completed cognitive, motor, and affective measures. A knowledgeable informant completed an ADL scale that asked about degree and perceived source of difficulty (cognitive, motor, affective) for each task. Results: Informants indicated that motor dysfunction was the most common source of ADL difficulty, but the informants viewed difficulty with certain tasks, such as financial management, as particularly related to cognitive dysfunction. Informant reports of the source of ADL dysfunction (cognitive, motor, affective) were consistent with clinical measures of those specific dysfunctions. ADL dysfunction attributed to cognition specifically (χ² = 9.80, p = .01) was higher in those with measurable cognitive impairment. Conclusions: Informant reports of the sources of ADL dysfunction correlate with clinical measures of these symptoms, suggesting that informants may provide useful clinical information about the cause of ADL dysfunction in persons with PD.