The authors performed this preliminary study to investigate the effect of softening E.C.T. and propofol was compared to pentothal for induction of anaesthesia for E.C.T on seizure duration. The results were follows ' 1) E.C.T. was performed in 60 psychiatric inpatients who were admitted during the study period. Of them 51.7% were diagnosed as schizophrenia, 21.6% as major depressive disorder, 16.7% as bipolar I disorder, manic and 10% of others. 2) Mean number of E.C.T. was 12.2 times a patient. 3) The most common target symptoms were persecutory delusion in schizophrenia, psychomotor retardation or agitation in major depressive disorder, and violent aggressive behavior in bipolar I disorder, manic. 4) Pre-ECT medication usually used were atropine 0.0093mg kg(-1), pentothal 2.76mg kg(-1) or propofol 1.42mg kg(-1). 5) The duration of seizure, as measured clinically, was reduced with propofol(20.5 sec) in comparison with pentothal(35.7 sec)(p<0.001). This suggest the possibility that additional treatment may be needed for the same clinical effect in psychiatric illness when propofol is used as the induction agent.