We compared subjective self-reports with objective performance ratings of activities of daily living (ADLs) and instrumental ADLs (IADLs) in patients with Parkinson's disease (PD) and identified variables associated with discordance of ratings between these two methods. Seventy-six PD patients completed a modified Older Americans Resources and Services scale, assessing ADLs and IADLs. These results were compared with structured performance tests of walking, eating, dressing, money, and medicine management administered in the clinic. Patient performance was rated on a five-point Likert-type scale, ranging from 1 = no difficulty to 5 = completely unable to perform task. Significant differences were found between patients and clinicians' ratings on all tasks except walking. On the other four tasks, paired group t tests showed that patients reported better function compared with the clinician rating of medication management (1.33 vs. 2.80), eating (1.53 vs. 1.76), dressing (1.64 vs. 1.86), and managing money (1.44 vs. 2.06). A discrepancy was found between patients subjective reporting of ADL and IADL function and objective ratings. Patients overestimated their function on four of five tasks. Further study is necessary to identify whether subjective or objective performance ratings are more reflective of actual daily function.