Intravenous urography (IVU) as it is used widely today was probably started in early 1950's after theintroduction of triiodobenzoic acid compounds as contrast media. This long cherished traditional method consistsof taking radiograms at 5, 15 and 25 minutes after the injection of contrast medium. There are a few modificationsof this standard urographic examination such as five minute IVU(Woodruff, 1959), minutesequence pyelogram (Maxwellet al., 1964), drip infusion pyelography (Schencker, 1964) and nephrotomography(Evans et al., 1955). The presentstudy has been undertaken to test if the conventional standard IVU can be more rapidly performed without losingessential informational contents of urograms. In this new clinical trial, urograms were taken at the end of 1,4,and 7 minutes instead of 5, 15 and 25 minutes after the intravenous injection of contrast medium. We injected 40ml of meglumine diatrizoate solution within 30 seconds using an 18G iv needle. (The amount of injected contrastmedium has been reduced recently to ordinary single dose of 20ml for subjects weighing less than 80 kg). Uponviewing the 7 minute film in front of an automatic processor, the examination was terminated after obtaining anupright view unless any further radiogram was indicated. As shown in Tables and Figures, our new 1-3-7 minutemethod has been proven to provide us with as much essential and useful informations as conventional 5-15-25 minuteurography. Thus, we were able to finish one examination within 10 minutes without losing any necessary diagnosticinformations. In some of patients with obstructive uropathy such as stone the examination was extended as long asit was desired. Side reactions were occasional nausea, flushing and rare mild vomiting which never prevented theexamination.