Twenty-four patients undergoing peripheral arteriography with iotrolan 280, a blood-isotonic, nonionic, dimeric contrast medium, were evaluated in a carefully controlled phase III open trial using a variety of objective and subjective tests of discomfort. There was almost no evidence of pain, and the patients reported that they had minimal warm sensation during injection. No abnormalities in blood chemistry or urinalysis were noted in relation to injection of the contrast medium. Opacification of the peripheral arteries was excellent in all patients. Multiple physical examinations, chemical tests, electrocardiograms, and monitoring of the blood pressure showed that iotrolan 280 was a safe and useful contrast agent for peripheral angiography.