The present study characterized 46 chronic fatigue syndrome (CFS) patients' experiences of CFS and compared these patients with 11 healthy control participants. Chronic fatigue syndrome patients reported more symptoms of CFS, distress, and functional impairment than the controls. These heightened symptoms remained relatively stable over time within the patient group. However, within individual patients, there were daily fluctuations in symptom reporting, indicating that some days were better than others. Additionally, there was a close association between CFS symptoms and reports of perceived stress and negative affect in the patient group. These results demonstrate the usefulness of the Daily Record Form for assessing symptom severity in CFS patients.