Trimeglamide is a central nervous system depressant. In the course of an investigation of new compounds with action on the central nervous system, trimethoxybenzoyl-glycine-diethylamide (Riker 548; trimeglamide) demonstrated the ability to induce in animals a state of somnolence which could not be distinguished from the physiologic state of sleep. The absence of hypnosis or anesthesia at five to ten times the effective soporific dose in dogs is rather unique and distinguishes trimeglamide from such used sedatives as barbiturates, chloral hydrate, methyprylon, ethchlorvynol and others. Trimeglamide has anticonvulsant effects in mice against supramaximal electroshock. In dogs, trimeglamide had a mild protective effect against apomorphine-induced emesis. The drug was generally ineffective in the treatment of anxiety symptoms associated with various psychiatric illnesses. In man, oral doses of 500 to 1500 mg caused sedation or drowsiness, or both, in half the cases. No spindling or drug-induced artifacts were found in electroencephalographic recordings.