Lactic acidosis (Type A) is common in critically ill patients and usually treated by correcting the underlying etiology. We present the case of a young female who presented with life-threatening lactic acidosis secondary to hematological malignancy. Timely initiation of hemodialysis was lifesaving. The case highlights the importance of considering Type B lactic acidosis (in this case secondary to a hematological malignancy) and also initiating renal replacement therapy when routine measures are ineffective.