The value of a drug in premedication still depends largely on its sedative properties. These are difficult to measure by subjective means alone or by any one simple test. Consideration of the objective signs of sleep and anxiety suggested that a scoring system could be developed which would yield additional information. An arbitrary scoring system has been devised; combining observation of the patient's subjective state with measurements of change in heart rate and blood pressure which occur in response to sedation and to a standard stimulus. The system has been tested in a series of 200 cases premedicated with drugs whose sedative effects are well known. These drugs were distinguished in a manner which appeared to correspond with clinical experience. Correlation between the individual tests and the total score was fairly satisfactory. It is suggested that the preliminary results form a basis for further work.