Non-ionic contrast medium iopromide (Ultravist) was compared with ionic contrast medium ioxitalamate (Telebrix) for efficacy and safety in 63 patients undergoing left ventriculography. In all patients adverse symp-toms and signs including pain heat sense nausea vomiting etc were cheked during and shortly after the injcection. Blood pressure heart rate EKG and left ventricular predssure were also monitored during the study and CBC, UA, BUN and creatinine were cheked before and 24 hours after the study. The cineangiographic films were analysed and compared by 2 radiologists for the quality. Serious adverse effect did not occur in any case. Minor effects especially nausea were less frequently caus-ed by non-ionic contrast medium than by ionic contrast medium and heat sense to non-ionic contrast medium was less severe than to ionic contrast medium. Except slightly elevated LVEDP at 1.5 minutes after the study in patients given ionic contrast medium there was no significant change of electrophysiologic parameters and laboratory findings in both groups. In regard to image quality there was no significant difference between ionic and non-ionic contrast medium Thus non-ionic contrast medium iopromide appears to be safer for use in left ventriculography than the conventional ionic contrast medium particularly in those patient at high risk of adverse effects.