The application of high gradient magnetic separation (HGMS) to shale oil has been shown by the authors to be an effective method for the removal of solid particles from these hydrocarbon streams. Typical ash removal results indicated that the solids concentration was reduced by 90-100% in several different types of shale oils and that temperature effects can be significant. Similar studies of coal and other synthetic fuels have demonstrated the usefulness of this technique in removing inorganic particulates, such as iron sulfides and pyrite, from liquid hydrocarbon streams. The application of magnetic separation methods to coal-derived liquids has been prompted by the large concentrations of iron containing compounds present in coal ash. By comparison, the mineral matter composition of most oil shales is not as rich in iron. However, the iron composition appears to be fairly evenly distributed enabling even very small solid particles to be efficiently separated from shale oil streams.