Volumetric ultrasound imaging opens the door to a variety of diagnostic and interventional investigations. A key to the utility of volumetric ultrasound imaging is the ability to produce high quality displays of the target in real time as data is acquired. We propose a rendering technique that enables volumetric visualization of data with arbitrary geometry at real time rates. An image is generated by blending a set of slices of the volume data orthogonal to the viewing direction. Each sample in each slice is assigned a color and transparency as a function of the nearest voxel data. Finding the voxel associated with each pixel is accomplished efficiently using a precalculated volume look-up table, which converts from the Cartesian viewing coordinate system to the arbitrary (typically spherical) coordinate system of the volume data. The volume rendering technique uses off the shelf hardware and is shown to be fast and flexible.