Chronic renal failure is commonly associated with acid-base disorders that are corrected with the institution of maintenance peritoneal dialysis. Severe shifts in systemic pH that occur in patients undergoing peritoneal dialysis are usually acidemic shifts due to inadequate replacement of the kidney's ability to excrete acid and regenerate bicarbonate. This report describes a severe alkalemic shift in pH in a patient undergoing continuous cyclic peritoneal dialysis due to a failure of dialysis to substitute for the kidney's normal response to simple respiratory alkalosis. This case emphasizes that in patients undergoing peritoneal dialysis, physicians must actively provide the "renal compensation" for an acid-base disorder and change the dialysis prescription.