Many technical problems, related to both imaging instrumentation and contrast agents, have to be taken into account before attempting non-invasive evaluation of myocardial perfusion by intravenous contrast media injection. Potentials and pitfalls of first generation contrast agents (i.e. Levovist, Schering AG, Berlin, Germany) using intermittent harmonic angio imaging and of second generation contrast media (i.e. SonoVue, Bracco SpA, Milan, Italy) using real-time perfusion imaging in the non-invasive assessment of myocardial perfusion were described and discussed. We still need more solid data before introducing intravenous myocardial echocardiography into the clinical arena. However, convincing data from several research laboratories are paving the way for the widespread use of this new method in clinical practice.