Hyperhidrosis is an annoying and frequently embarassing symptom that is difficult to control. In the first case to be reported, the efficacy of mephobarbital (mebaral®) in the control of excessive sweating was observed incidental to the use of the drug in a convulsive disorder. In the second case, mephobarbital was employed specifically for hyperhidrosis. REPORT OF CASES On Nov. 9, 1950, a 61-year-old, white, childless widow was admitted to the hospital complaining of general nervousness, high blood pressure, excessive use of barbiturates and alcohol, insomnia, incoordination, and excessive sweating. For over five years she had taken pentobarbital, 0.1 gm., or amobarbital (amytal®) sodium, 0.2 gm., at bedtime as well as phenobarbital in unknown quantities during the day. The barbiturates and alcohol had produced difficulty with ocular focus, incoordination, and ataxia to a degree that required walking with a cane. Sensitivity to heat was marked, and the patient would perspire when