Non-ionic contrast media iopromide (Ultravist) was compared with ioxitalamate (Telebrix) and/or iox-aglate (Hexabrix) for efficacy and safety in 203 patients undergoing cardiac angiography neurovascular angiography peripheral and visceral angiography and intravenous pyelography. In all patients adverse symp-toms and signs including heat sense pain nausea vomiting etc. were checked during and after the injection. In addition EKG and LV pressure were monitored during the cardiac angiography. And also CBC, UA, BUN and creatinine were cheked before and 24 hours after the cardiac angiography. Serious adverse effect did not occur in any case. Minor effects such nausea and abdominal pain were less frequently caused by non-ionic contrast media than by ionic contrast media especialy in cardiac angiography and intravenous pyelography. There was no significant difference between ionic and non-ionic contrast media in regard to electrophsiologic parmeters such as EKG and LV pressure. In case of intravenous pyelography nonionic contrast media seemed to be superior to ionic contrast media in image quality. It is suggested that in spite of higher cost non-ionic contrast media be needed for the safety and image quality particularly in those patients at high risk of adverse effects by ionic contrast media.