Hypophosphatemia and its consequences have received considerable attention due to their frequency and occurrence in a wide spectrum of clinical disorders.1–7The cardiac, pulmonary, neurological, and hematological complications of hypophosphatemia offer ample justification for implementing therapy in the setting of phosphorus depletion. However, the goals of such therapy are poorly defined because serum phosphate levels may not reflect total body stores of phosphorus.8Despite its popularity, little comment has been made in the medical literature concerning adverse reactions of phosphate therapy. In this regard, two case histories are presented to illustrate the potential complications of overgenerous phosphate therapy.