BACKGROUND: After radiological procedures, the incidence of acute renal failure varies greatly, and cholesterol embolism may not always be recognized. Little, if anything, is known about whether recommendations for the prevention of either complication are correctly implemented. METHODS: We performed a prospective epidemiological study in a large population (n=809) of consecutive inpatients in a university hospital. The patients were monitored for risk factors, ongoing medications, and details of preventive measures and of radiological procedures. Contrast nephropathy was defined as a 25% rise in serum creatinine. Cholesterol embolism was defined by the presence of two typical signs. We analyzed the incidence, risk factors, and prevention of contrast nephropathy and cholesterol embolism. RESULTS: The most frequent procedure that our patients underwent was cardiac angiography (50%). The incidence of contrast nephropathy was 7%. We confirmed the classical risk factors (diabetes, dose of contrast medium, and renal insufficiency) and added potentially nephrotoxic medications as an independent risk factor. Fluid therapy, commonly proposed in high-risk patients, was adequately carried out in only 12% of patients. The incidence of cholesterol embolism was 4%, with 10% renal involvement. Arteriosclerosis and renal insufficiency were risk factors, but anticoagulation therapy was not. CONCLUSION: Adequate fluid therapy and discontinuation of nephrotoxic medications should be more systematically implemented in the prevention of contrast nephropathy. Recognition of cholesterol embolism is crucial.