The value of clinical decision on antibiotic treatment of fever episodes following transurethral resection of the prostate was assessed in 134 patients. Besides bacteriuria, need of blood transfusions and various catheter problems were associated with a significant number of fever episodes. The majority of patients with fever not given antibiotic therapy had negative urine cultures (90%), whereas 41 % of the patients with fever treated with antibiotics showed negative urine cultures indicating an overtreatment of these patients. Out of the total number of patients, only 10% with subsequent negative urine cultures received antibiotics, a figure which should be compared to the inevitable rate of overtreatment when general antibiotic prophylaxis is preferred.