Abstract In situ retorting of oil shale requires explosive loading, hydrofracturing or other treatments to produce the bed porosity necessary for a self-sustaining burn. Fundamental to the understanding of the fracturing behavior are the compressive properties of oil shale subject to loading at different strain rates. Uniaxial testing of oil shale from the Green River Formation in Wyoming indicates that the compressive fracturing strength is strongly dependent on organic volume and on strain-rate. Failure modes ranged from brittle for lean samples to ductile for rich ones. A strain-rate dependency failure mechanism is presented. Data from stress and strain measurements together with combustion analysis data for organic volume were used in multiple regression computer programs to demonstrate correlation between ultimate compressive stresses, strain-rate, and oil shale composition. A linear relationship was observed among the ultimate stress, organic volume, and the logarithmic strain-rate. The linear relationship enables the ultimate stress to be extrapolated at the explosive strain-rates for different oil yields with confidence. The influence of organic volume and strain-rate upon the ultimate strain and Young's modulus were also investigated.