The purpose of this preliminary study was to investigate the inter-rater reliability among physician, patient, and caregiver ratings on the Hoehn & Yahr (H & Y) and Schwab & England (S & E) rating instruments. We also examined differences in ratings between patients who attended clinic with and without caregivers (spouses and adult children). Patients and caregivers coming for an appointment at Colorado Neurological Institute were asked to independently complete the H & Y and S & E scales. Physicians rated the patients during the exam. In the group of patients who came to clinic with caregivers, there was significant agreement on both the H & Y and S & E (P<0.001). For patients not accompanied by caregivers, patients rated themselves as more debilitated on the S & E than physicians (P<0.001). Patients without caregivers rated themselves as more functional than patients with caregivers on both scales (P<0.001). Physicians also rated patients without caregivers as more functional on both scales (P<0.001). Results indicated there was consistency among ratings of physicians and patients accompanied by caregivers on both scales. Patients attending clinic alone rated themselves as worse on the S & E than physicians. Patients alone were rated as more functional than patients accompanied by caregivers on both scales regardless of rater.