Objective To compare the influence of different iodinated contrast media with several dilutions on plaque attenuation in an ex vivo coronary model studied by multislice CT coronary angiography. Methods In six ex vivo left anterior descending coronary arteries immersed in oil, CT (slices/collimation 64×0.625 mm, temporal resolution 210 ms, pitch 0.2) was performed after intracoronary injection of a saline solution, and solutions of a dimeric isosmolar contrast medium (Iodixanol 320 mgI ml(-1)) and a monomeric high-iodinated contrast medium (Iomeprol 400 mgI ml(-1)) with dilutions of 1/80 (low concentration), 1/50 (medium concentration), 1/40 (high concentration) and 1/20 (very high concentration). Two radiologists drew regions of interest in the lumen and in calcified and non-calcified plaques for each solution. 29 cross-sections with non-calcified plaques and 32 cross-sections with calcified plaques were evaluated. Results Both contrast media showed different attenuation values within lumen and plaque (p<0.0001). The correlation between lumen and non-calcified plaque values was good (Iodixanol r=0.793, Iomeprol r=0.647). Clustered medium- and high-concentration solutions showed similar plaque attenuation values, signal-to-noise ratios (SNRs) (non-calcified plaque: medium solution SNR 31.3±15 vs 31.4±20, high solution SNR 39.4±17 vs 37.4±22; calcified plaque: medium solution SNR 305.2±133 vs 298.8±132, high solution SNR 323.9±138 vs 293±123) and derived contrast-to-noise ratios (p>0.05). Conclusion Differently iodinated contrast media have a similar influence on plaque attenuation profiles. Advances in knowledge Since iodine load affects coronary plaque attenuation linearly, different contrast media may be equally employed for coronary atherosclerotic plaque imaging.