We prospectively followed a cohort of 64 patients bearing an aortic or mitral prosthetic valve (mean follow-up 5.2 +/- 3.2 months) in order to evaluate if color-coded two-dimensional Doppler echocardiography (CFD) could provide some major advantages with respect to pulsed (PW) and continuous wave (CW) Doppler in the diagnostic accuracy of detection of intra-, and paraprosthetic leaks. During follow-up 4 cases of pathologic prosthetic regurgitation ensued and were all correctly and easily identified by CFD while one of them was missed both by PW and CW Doppler. Based on our results we conclude that CFD is the best noninvasive tool actually available for the correct identification of prosthetic valvular regurgitation because it can provide useful accessory information difficult to obtain with other echocardiographic techniques.