OBJECTIVE: To examine the nature and scope of pain in persons with cerebral palsy (CP). DESIGN: Standardized interviews to assess demographics, pain experiences, and the impact of pain on activities. SUBJECTS: Ninety-three adults with CP recruited from medical clinics at the University of Washington and local residential and community housing for persons with developmental disabilities. MAIN OUTCOME MEASURES: Weekly and 3-month pain intensities, chronic pain grade, interference in daily activities caused by pain, and pain-exacerbating and pain-relieving factors. RESULTS: Sixty-two subjects (67\%) reported one or more areas of pain of > or =3 months' duration. Lower extremity pain and back pain were the most common complaints. Fifty-six percent of the subjects reporting pain indicated it occurred daily. Mean average pain intensity, graded on a scale of 0 (no pain) to 10 (pain as bad as could be), was 3.16 (SD = 2.45) in the preceding week and 4.45 (SD = 2.34) in the previous 3 months. Approximately 53\% of subjects reporting pain indicated their average pain was of moderate to severe intensity (average pain rated as > or =5). Using Von Korff's Chronic Pain Grade classification system, the majority of subjects who reported pain fell into either grade I (low disability, low pain intensity; 51\%) or grade II (low disability, high pain intensity; 39\%). Subjects reported many factors that exacerbate pain (eg, stress or weather) or decrease it (eg, exercise or rest). CONCLUSIONS: The data suggest that pain is common in adults with CP. In many subjects, pain levels were moderate to intense.