We report a case of transurethral resection of prostate (TURP) syndrome. A 78-year-old man with prostatic hypertrophy was scheduled for transurethral resection of the prostate under spinal anesthesia. 30 minutes after the end of the surgery, the patient presented signs of TURP syndrome with bradycardia, arterial hypotension, cyanosis, hypoxemia and coma. The electrolytes analysis revealed an acute hyponatremia (sodium concentration 125 mmol/L). Medical treatment consisted of hypertonic saline solution 3%, volume expansion, intubation and ventilation. The presented case describes a typical TURP syndrome, which was diagnosed and treated early. The patient was discharged from hospital without any complications.