Pilot data on mood and anxiety changes in 15 Parkinson's disease patients with motor fluctuations are described based on ratings every 30 min for 5 h bracketing a 2-h constant-rate levodopa infusion. Robust mood and anxiety effects slightly preceded but temporally paralleled fluctuations in motor tapping scores. Research nurse ratings blind to patient ratings corroborated the changes. The magnitude of changes in mood and anxiety scores did not correlate with the magnitude of changes in tapping scores. The findings of this uncontrolled study suggest mood and anxiety fluctuations may be a common and potentially important component of levodopa-induced fluctuations.