The triplet potential energy surface for the reaction of cobalt cation with propane has been studied along the two main reaction pathways leading to the formation of (i) hydrogen and propene and (ii) methane and ethene. Effective core potentials for all elements have been used for all calculations. The geometries have been optimized at the complete active space self-consistent field (CASSCF) level of theory, and the final energetics have been refined at the multireference second-order perturbation theory (MRMP2) level with polarization function augmented basis sets. Reasonable agreement with the experimental energetics has been obtained, and the predicted mechanism is consistent with the experimentally determined mechanism of Haynes, Fisher, and Armentrout (J. Phys. Chem. 1996, 100, 18300).