The contrast media-induced renal effects of 3 different low osmolar contrast agents were prospectively evaluated with creatinine, beta-2-microglobulin, and urea in serum before and after femoral arteriography in 110 consecutive patients. Forty-two patients (38%) had at least one of the 2 major risk factors for contrast media-induced nephropathy; diabetes mellitus or renal dysfunction. Six patients (5%) had both risk factors. There were statistically significant increases of S-creatinine (6.5%, p < 0.001) and S-beta-2-microglobulin (7.4%, p < 0.001) but no increase of S-urea, in the total patient material. This effect was independent of preexaminatory renal function, the presence of diabetes mellitus and type of low osmolar contrast agent used in these patients who were properly hydrated before the examination. The amount of administered contrast medium did not correlate with the degree of contrast agent-induced renal function impairment.