We report a 20-year-old man who presented to our emergency room with a history of polyuria, weakness, constipation, nausea, and vomiting of two months duration. History and clinical examination revealed a significant weight loss and mild hepatomegaly. Laboratory investigations revealed hypokalemia, hypernatremia, and severe metabolic acidosis and anemia. Ultra-sound of the abdomen revealed enlarged kidneys without hydronerphrosis. The patient developed paralysis due to further decline in serum potassium level, which improved after an aggressive fluid and electrolyte management. He was investigated extensively for polyuria and type of acidosis. The kidney biopsy showed interstitial leukemic infiltration. He was managed accordingly and recovered from the condition. This case demonstrates an unusual presentation of a hematological malignancy, which was a diagnostic as well as a management challenge.