ARTICLE INFO _________________________________________________________ ___________________Purpose: To compare urodynamic characteristics in patients with idiopathic detrusor overactivity (IDO) with those of an age matched cohort with diabetes mellitus (DM) and detrusor overactivity (DO). Secondly, to determine whether urodynamic features could help distinguish these two groups of patients. Materials and Methods: Urodynamic data was collected on 58 female patients; 29 with IDO and 29 with DM and detrusor overactivity. Eight urodynamic parameters were selected for analysis: amplitude of the first overactive contraction (AOFC), the volume at the first contraction, cystometric capacity, maximal detrusor pressure, maximal flow rate, voiding pressure at maximal flow, voided volume and postvoid residual (PVR) urine volume. Finally, sensitivity analysis for distinguishing urodynamic parameters between studied groups was performed. Results: AOFC, volume at AOFC and maximal detrusor pressure were statistically greater in diabetic patients, compared with the non-diabetic group of women (16.00 cm H 2 O versus 9.00 cm H 2 O, 309.00 mL versus 167.00 mL and 76.48 cm H 2 O versus 55.41 cm H 2 O respectively). A specificity of 72.41% and positive predictive value of 71.43% were achieved for AOFC with cutoff value of 12 cm H 2 O. These parameters were further improved with cutoff value of 258 mL for volume at AOFC and were 75.86% and 73.08% respectively. Conclusions: Certain urodynamic parameters in diabetic female patients with DO are shown to be significantly different than those in women with IDO. Further prospective study should provide additional information about the pathogenesis and progression of DO in diabetic patients as well as the validity of diabetic screening in patients with IDO.