To evaluate the bladder functions by urodynamic studies in diabetic patients with lower urinary tract symptoms (LUTS).Methods Urodynamic studies were performed in 42 diabetic patients (24 men and 18 women;age range,38-78 years).The diabetic history of the patients was from 1 month to 25 years.Results Of the 41 cases who underwent all items of urodynamic examination,38 cases (93%) had abnormal findings and 3 (7%),normal.The detrusor was underactive in 14 cases (34%) and areflexia in 10 (24%);BOO was found in 13 (32%).One female patient had stress urinary incontinence.Conclusion There is a high prevalence of bladder dysfunction in diabetic patients with LUTS.It is necessary to perform urodynamic studies in diabetic patients before initiation of therapy,especially in patients who are assigned to undergo bladder and urethral surgery.Preoperative urodynamic studies can contribute to the surgical success rate.11 refs,1 tab. To evaluate the bladder functions by urodynamic studies in diabetic patients with lower urinary tract symptoms (LUTS). Methods Urodynamic studies were conducted in 42 diabetic patients (24 men and 18 women; age range, 38-78 years). Diabetic history of the patients were from 1 month to 25 years. Results of the 41 cases who underwent all items of urodynamic examination, 38 cases (93%) had abnormal findings and 3 (7%), normal.The detrusor was underactive in 14 cases (34% ) and areflexia in 10 (24%); BOO was found in 13 (32%). One female patient had stress urinary incontinence. Confound There is a high prevalence of bladder dysfunction in diabetic patients with LUTS. It is necessary to perform urodynamic studies in diabetic patients before initiation of therapy, especially in patients who are assigned to undergo bladder and urethral surgery. Preoperative urodynamic studies can contribute to the surgical success rate. 11 refs, 1 tab.