Disorders of the autonomic nervous system are common in Parkinson's disease (PD). Earlier studies suggest that some nonmotor symptoms may fluctuate with the motor symptoms, but the possible interrelationship between motor phenomena and sweating has not been studied. The authors measured sweating by using an evaporimeter on three different areas of the body (right hand, left hand, chest) immediately before the morning PD medication (baseline), and thereafter hourly up to 4 hour, in 16 PD patients with wearing-off type of motor fluctuations and in 15 patients without clinical motor fluctuations. The clinical state of the patients was evaluated using the Unified Parkinson's Disease Rating Scale motor score every hour. Sweating increased during the 4-hour follow-up, and reached its maximum level at the time of the highest Unified Parkinson's Disease Rating Scale motor score phase (off-stage) in patients with wearing-off (initially affected hand, P = 0.007; left hand, P = 0.004; right hand, P = 0.034), but in the patients without wearing-off no changes in sweating were observed during the follow-up. Sweating of the left hand (P < 0.001), right hand (P < 0.001), and initially affected hand (P = 0.008) during the whole observation period was significantly higher in patients with motor fluctuations than in those without. The present study shows that sweating fluctuates in conjunction with wearing-off phenomenon.