Tumor lysis syndrome is characterized by multiple metabolic derangements resulting from the release of intracellular components into the bloodstream due to abrupt malignant cell death, spontaneously or following antineoplastic therapy. The syndrome is characterized by hyperkalemia, hyperuricemia, hyperphosphatemia, and hypocalcemia, while deposition of uric acid and calcium phosphate crystals may result in acute renal failure, which is often exacerbated by concomitant intravascular volume depletion. A case of tumor lysis syndrome complicated by acute renal failure in a patient with non-Hodgkin's lymphoma is reported and the pathophysiology, the clinical features, and the treatment options are discussed.