To evaluate diagnostic quality, safety and local tolerance in peripheral arteriography, isotrolan (280 mg iodine/ml) was compared to the non-ionic monimers iopamidol (300 mg iodine/ml), iohexol (300 mg iodine/ml) and iopromide (300 mg iodine/ml) in nine randomized, double-blind, the suitability of iotrolan 280 was evaluated in an interindividual, non-randomized, single-blind study. Pelvic-leg arteriography was performed in 298 patients, selctive femoral arteriography in 201, intra-arterial digital subtraction angiography in 20. Despite the 7% lower iodine content of iotrolan, its contrast density was rated as good as that of the non-ionic monomers. Due to the few motion artifact, caused by motor pain reactions, the overall diagnostic quality of iotrolan was good. The slightly higher viscosity of iotrolan did not impair injectability. General tolerance was excellent with iotrolan and with non-ionic monomers (2.3% minor adverse events versus 4.6%). With respect to local tolerance, iotrolan demonstrated clear advantages. The frequency of completely painless injections was 91% in non-selective femoral angiography and 70% in penile arteiorgraphy (62, 25 and 10%, respectively, with comparator agents). in intra-arterial DSA of the hand, the injectio of iotrlan 280 was tolerated with minimal or no pain in 100% of patients (58% with iohexol 300). Iotrolan proved to be highly suitable for peripheral arteriography and for arteriography of the penis. Its major advantage is excellent local tolerance in examinations in which even low-osmolar non-ionic monomers may cause significant pain and unpleasant sensations of heat. Better local tolerance results in an improvement of diagnostic quality due to fewer motion artifacts.