A case of thalamic pain syndrome in which gratifying and dramatic relief was obtained with chlorpromazine is described. This patient, who had been incapacitated for 9 months and who had made 4 suicidal attempts because of pain, has been maintained in a comfortable state for almost a year and a half while taking this medication. Two attempts to withdraw the drug without the patient''s knowledge by substituting a less potent or a placebo capsule, and another attempt by the patient to voluntarily discontinue the medication, resulted in a prompt recurrence of the intense symptoms.