A review of the current knowledge of the anti-thrombotic properties of iodinated contrast media (CM) has been conducted. CM are classified according to their chemical structure, either ionic or non-ionic (monomeric or dimeric). Numerous in vitro and in vivo data show that, although all CM have anti-coagulant properties, ionic molecules are more potent than non-ionic and, furthermore, do not activate resting platelets, unlike non-ionic agents. These properties may lead to a decrease in thrombus formation during interventional procedures. Several clinical trials have shown that CM may play a role in the occurrence of acute thrombotic complications but also in delayed ischaemic events during interventional procedures. A recent meta-analysis showed that, compared to non-ionic monomers, ionic low-osmolar CM reduce the rate of coronary artery abrupt closure, but no significant difference was found with respect to ischaemic complications. Ionic CM lead to a lower deposit of thrombotic materials on catheters and guide-wires. To date, clinical data comparing ionic CM and non-ionic dimers are scarce, significantly heterogeneous and, unlike experimental data, they do not show differences between both classes of CM. Further studies are required to better understand the precise mechanisms of such interactions and to analyse the effect of CM when new antiplatelet agents or new procedures (stenting) are used, to comply with new clinical strategies.