Water intoxication from intravascular absorption of non-electrolyte irrigating fluid is a well-known and often serious complication of transurethral resection of the prostate. The amount of absorbed fluid depends on the duration of the operative procedure, the number of transected open venous sinuses and the hydrostatic pressure of the irrigating fluid. Arterial hypertension, bradycardia, mental agitation, confusion, headache, nausea, dyspnoea, convulsions and pulmonary edema are the typical syndromes. In this case, severe Angina Pectoris was the first alarming symptom.