The present invention relates to non-lethal methods of conditioning a recipient for bone marrow transplantation. In particular, it relates to the use of sublethal doses of total body irradiation, cell type-specific antibodies, especially antibodies directed to bone marrow stromal cell markers, cytotoxic drugs, or a combination thereof. The methods of the invention have a wide range of applications, including, but not limited to, the conditioning of an individual for hematopoietic reconstitution by bone marrow transplantation for the treatment of hematologic malignancies, hematologic disorders, autoimmunity, infectious diseases such as acquired immunodeficiency syndrome, and the engraftment of bone marrow cells to induce tolerance for solid organ, tissue and cellular transplantation.