Tumor lysis syndrome (TLS) is a well recognized complication of chemotherapy and radiotherapy for leukemia, lymphoma as well as rapidly growing malignancies. Less described is the occurrence of TLS following steroid therapy alone. Herein, we report on a 32-year-old male with myelodysplastic syndrome, characterized by refractory anemia with excess blasts in transformation, who developed acute oliguric renal failure 12 hours after methylprednisolone 1.0 g for presumed autoimmune thrombocytopenia. Laboratory investigations revealed typical findings of TLS, including hyperkalemia, marked hyperuricemia, hyperphosphotemia, hypocalcemia and urine uric acid to creatinine ratio 1.8 (> 1.0). Long hemodialysis (8 hours) was initiated for 3 consecutive sessions. Renal function recovered 1 week later. This case high-lights that single-dose steroid administration in a patient with hematological malignancy may cause the potential life-threatening complications of TLS. Prophylactic management prior to the use of steroid therapy for a variety of purposes is absolutely required in high-risk patients.