Waste disposal schemes using spent shale in embankments require a thorough knowledge of its geotechnical engineering properties for environmentally safe disposal. In this context, the objective of this laboratory investigation was to determine the physical properties, geotechnical properties, and composition of spent oil shale retorted by the PARAHO and TOSCO processes. Physical properties consisted of mechanical analyses, Atterberg limits, and specific gravity determinations. Geotechnical engineering properties were determined by compaction, maximum-minimum density, unconfined compression, triaxial compression, and permeability, direct shear, Ko, cyclic triaxial, resonant column, and Los Angeles Abrasion test. Petrographic, chemical, and scanning electron microscopy analyses were used to determine compositional features.