A microanalytical technique, selective destructive demagnetization (SDD), enables one, relatively simply and reliably, to determine the three-dimensional, small-scale distribution of magnetic properties in rocks. SDD is particularly useful in studies of remanence distribution. Lab preparation for the method entails the progressive slicing of a core specimen into a series of discs, each of which is lapped down to a one-grain-diameter thickness. Subsequently, grains selected on some physical property, such as size, shape, color, or position, are selectively removed from the disc by either physical (drilling, cutting) or chemical (acid leaching) means. Comparison of magnetic measurements made prior to and after grain removal permits determination of the designated magnetic property carried by the grains. Data acquired thus far from several different kinds of rocks show that SDD has potential usefulness in rock-magnetic studies.