Three-dimensional (3-D) echocardiography has been an important research goal ever since the introduction of two-dimensional (2-D) echocardiography. Most approaches towards 3-D echocardiography were off-line and based on the sequential rotational scanning and acquisition of multiple cross-sectional images together with external or internal reference systems. These approaches were limited by long acquisition and analysis time in combination with poor image quality. Recently, improvements in the matrix array technology have significantly increased spatial and temporal resolution of second-generation real-time 3-D transducers. Clinical use of modern 3-D echocardiography is boosted by the marked reduction in acquisition time and the unique possibility of on-line rendering on the ultrasound system. The integration and future quantification of new parameters together with on-line review allows new insights into cardiac function, morphology and synchrony that offer great potentials in the evaluation of right and left global and regional function, diagnosis of small areas of ischemia, congenital and valvular heart disease and effects of biventricular pacing in dilated heart asynchrony. This report will review current and future applications of 3-D data acquisition, emphasizing the real-time methods and clinical applications of the new matrix array transducer.