Abstract The use of non-volatile sedative and other drugs before operation to prepare the patient for anesthesia and surgical manipulation is common practice. Preanesthetic sedation is a rational procedure based upon well established principles; these principles have been discussed. The pharmacologic actions of the drugs commonly employed have been described briefly. Factors which may modify the choice of drug, in individual cases, are also presented. No single drug or combination of drugs can be suited to all cases. Satisfactory results are obtained clinically by various individuals using different drugs, with the same general actions. Experience in the use of any of these drugs, particularly with regard to the adjustment of dose and time factor will result in increasing success. Routine prescription without individualization cannot be satisfactory. The most consistently good results are obtained when the various influencing factors are carefully weighed, the available drugs considered and following the choice and administration, the effects both advantageous and otherwise accurately observed and recorded. The anesthetist, who is thoroughly grounded in the physiologic and pharmacologic principles of sedative drug prescription, experienced in assessment of the varying factors in individual cases, and familiar with the conditions under which the anesthesia and operation are to be performed is best fitted to prescribe sedation for any patient. Training and experience are more often reflected in the success or failure of preanesthetic medication than in any other phase of the anesthetic procedure.