A miniaturized hand-held ultrasound scanner that permits two-dimensional echocardiography is described. The device has been routinely used in our emergency department, coronary care unit, wards, and outpatient department. The device has advantages in situations where rapid decisions are demanded of the expert echocardiographer. It permits improved bedside analysis of patients with puzzling cardiac conditions. An important feature is that the instrument can be used as a substitute for cardiac fluoroscopy in office practice. Tests performed in 100 consecutive patients have demonstrated that reasonable semiquantitative estimation of the sizes of left-side heart structures is possible. This new-generation instrument can make diagnostic ultrasound more readily available in emergency situations and should have considerable influence on the use of cardiac ultrasound for bedside diagnosis. It will undoubtedly affect future developments in automatic, portable, and special dedicated ultrasound equipment.