The authors report a documented case of hyperphosphatemia‐induced nephrocalcinosis after chemotherapy of an acute lymphoblastic leukemia (ALL). Microscopic examination of the kidney showed numerous calcium deposits with concentric structure in the calyces and in the tubules. Electronic microsound analysis proved the deposits to be composed of calcium phosphate. The nephropathy mechanism is studied, and a review of the 34 similar cases of this acute tumor lysis syndrome is made. Some suggestions are put forward to present the consequences of this therapy‐induced syndrome.