Although Parkinsonian tremors typically disappear during sleep and are reduced during relaxation periods, the effects of hypnosis on this type of movement disorder have been generally ignored. We observed a patient's severe Parkinsonian tremor under hypnosis and monitored it with EEG and EMG studies. The patient was taught self-hypnosis and performed it three to four times daily in conjunction with taking medication. The results suggest that daily sessions of self-hypnosis can be a useful therapeutic adjunct in the treatment of Parkinsonian tremors.