PURPOSE: Acute renal failure is a known complication of contrast media (CM) application in risk patients. Therefore an efficient prevention is highly desirable. The purpose of this pilot study was a) to demonstrate the efficacy and safety of prostaglandin E1 (PGE1 = alprostadil) in the prophylaxis against CM associated renal dysfunction in patients with renal disease, and b) to identify the adequate dose. METHODS: A total of 130 patients with renal dysfunction who were scheduled for intravascular CM administration were enrolled. They received PGE1 (10, 20, or 40 ng/kg/min) or placebo intravenously over a period of six hours (beginning one hour prior to exposure). Efficacy was determined by measuring serum creatinine and creatinine clearance. Safety was assessed by recording adverse experiences throughout the study and close monitoring of vital parameters especially during study drug administration. RESULTS: PGE1 proved to be superior to placebo in all doses. The dose of 20 ng/kg/min was most promising due to the lowest increase of serum creatinine 48 hours after CM administration. With respect to creatinine clearance, no relevant differences between study and control groups were observed. CONCLUSION: Our results suggest that intravenously administered PGE1 may be efficient in preventing CM-induced renal dysfunction in patients with renal impairment.