Thrombocytopenia occurs at various grades of severity in patients with malignancies undergoing myelosuppressive chemotherapy. In most instances, this is the major dose-limiting hematologic toxicity, especially in the treatment of potentially curable cancers. The standard preventive measure against chemotherapy-induced thrombocytopenia has been dose reduction and/or dose delay. This can often lead to poor outcomes, including reduced disease free periods and overall survival. With the availability of a platelet growth factor, recombinant human interleukin (IL)-11, an effective way to prevent chemotherapy-induced thrombocytopenia and accelerate platelet recovery, can now be provided to patients. The use of recombinant human IL-11 has also been extended to include patients with prolonged thrombocytopenia, such as those with bone marrow failure syndromes. With the use of recombinant human IL-11 in both malignant and non-malignant conditions, adverse reactions often seen with platelet transfusions, such as transfusion reactions, viral and bacterial infections and platelet refractoriness, can now be decreased or avoided.