Results of recent calculations aimed at predicting the liquid-crystalline phase behavior of binary mixtures of hard spherocylinders are shortly reviewed. These calculations have been made by adopting a simple, re-summed second-virial Onsager-type theory, and include, among the usual isotropic and nematic phases, smectic phases too. The paradigmatic hard spherocylinders with diameter D and length of the cylindrical part equal to 5D have been taken as reference component, to which hard spherocylinders of different geometry are added. The liquid-crystalline phase diagram of the bidisperse mixtures so generated have been traced in all range of composition as a function of pressure. Various phenomena, such as strong demixing, presence of triple, critical and azeotropic points, and smectic phases with different symmetries, have been observed.