In our study, we compared the effects of monopolar and bipolar resectoscope use on hemodynamics, serum electrolytes, and length of hospital stay of patients who is undergoing TUR-P with spinal anesthesia, After approval of the Faculty Ethical Committee and the written consent of the patients, 60 patients are randomly allocated into two groups that is planned to perform TUR-P with bipolar resectoscope (Group B)(n=30) group and monopolar resectoscope (Group M)(n=30), respectively. Spinal anesthesia had been performed to all patients. Blood pressure, heart rate and respiratory rate were monitorized with five minutes periods during the operation. Serum Na+ K+, Cl-, Hb ve Hct values measured before the operation, at 30, minute of the operation, 1., 29. h after the operation. Urethral catheterization time and length of hospital stay had been recorded. In Group M, blood pressure of the patients at 25th and 30th minutes had been decreased significantly comparison to the control values (p<0.05). Serum Na+ values at intraoperative 30th min, postoperative 1th, 24th of the patients in group M had been reduced significantly in comparison with the preoperative values; serum K+, Hb, Hct values at the postoperative 1st, 24th hours reduced significantly in comparison with the preoperative values (p<0.05). However, none of the patients in Group M had TUR syndrome. We observed that, in bipolar TURP method duration of the operation and length of hospttal stay were found significantly short, as well as hemoctynamic stabdity and electrolyte balance were found better than in monopolar TURF, method.