[en] Three modern low osmolar contrast media (Iopamiro, Omnipaque and Hexabrix) were injected intravenously in 150 patients. They were all effective for urography in a concentration isoosmolar to blood and with a dose of 90 mg I/kg body weight in patients with normal renal function. In patients with decreased renal function, this low dose is not sufficient and should be doubled. No significant diagnostic differences between the three media were found. The subjective and objective adverse effects were minimal and transient. (orig.)