The risk of developing contrast media-induced acute renal failure was studied in 49 randomly selected nonazotemic type 2 adult diabetic patients subjected to IVU. There were 19 men and 30 women in the group whose mean age was 62 +/- 10 years (range, 38 to 82 years). In preparation for IVU, patients were neither dehydrated nor given a laxative. The IVU was performed in the morning, using sodium diatrizoate and meglumine diatrizoate. Serum creatinine levels were measured pre-IVU and on days 1, 3, and 6 after the IVU. A total of three patients (6%) had an elevation of serum creatinine greater than 25% above the baseline by post-IVU day 3. One patient developed oliguria (less than 400 ml/24 hr) that lasted 2 days. Creatinine clearances of the three patients showing contrast media toxicity were 74, 60, and 105 ml/min pre-IVU. In each of the three patients, a return to pre-IVU serum creatinine concentration was noted within 2 weeks. It is concluded that the risk of acute renal failure post-IVU is small in hydrated nonazotemic type 2 diabetic patients.