Since the introduction of curare to modify the contractions in E.C.T., the use of relaxants has become standard psychiatric practice. These substances reduce the risk of fractures and enable treatment to be given to patients who would otherwise be denied it owing to risks arising from concomitant physical disease. During recent years great efforts have been made to simplify the technique of muscle relaxation, in particular to evolve a method which is short in duration, free from undesirable side-effects and easy in use. In this short paper we give a description of our experience with three drugs recently introduced, namely, Suxamethonium Bromide or Brevidil “M” which we used in 111 treatments, Suxethonium Bromide or Brevidil “E” (70 treatments), and Suxamethonium Chloride or Scoline (653 treatments). These choline succinic ester derivatives have similar characteristics which can be considered together.