The use of ultrasonography in cardiology has progressed so dramatically that not only is anatomic information available but information can also be derived about cardiac hemodynamics. Applications range from intravascular ultrasonic imaging of coronary atherosclerosis to predictions of the severity of fetal valvular pulmonic stenosis detected in utero. We reviewed cardiac ultrasonography as utilized in B-mode imaging, pulsed and continuous-wave spectral Doppler, and Doppler color flow mapping. We reviewed specialized areas, including stress echo for wall motion analysis, valvular and congenital heart disease applications, and new applications in intraoperative, transesophageal, contrast echography, coronary imaging, and fetal echocardiography. Finally, future applications of quantitative flow mapping and intraluminal and interventional ultrasonography were considered along with the required technological advances.