This invention provides therapeutic treatments that prevent or ameliorate thrombocytopenia based on administration of small RNA fragments. More specifically, this invention provides an improved chemotherapeutic regimen that prevents or ameliorates bone marrow suppression and thrombocytopenia induced by anti-cancer drugs, wherein the chemotherapeutic regimen incorporates administration of small RNA fragments. Further, the present invention provides a therapeutic treatment for thrombocytopenia associated with immune disorders known as Immune Thrombocytopenic Purpura based on administration of small RNA fragments.