Background: In men, bladder wall thickness ≥5 mm seems to be a useful predictor of outlet obstruction, with a diagnostic value exceeding that of free uroflowmetry indices. There are no data in the literature examining whether this may also apply in women. Aims: To identify the relationships between detrusor wall thickness (DWT) and symptoms and urodynamic findings suggestive of voiding dysfunction. Methods: This is a retrospective study analysing data sets of 686 women seen for urodynamic testing in a tertiary urogynaecological unit. Hesitancy, poor stream and stop-start voiding were recorded as symptoms of voiding dysfunction. All women underwent free uroflowmetry and multichannel urodynamic testing. We used the urethral resistance factor (URA) and the obstruction coefficient (OCO), methods employed to quantify bladder outlet resistance in men. Transperineal ultrasound for DWT was performed after voiding and catheter removal. Statistical analysis was carried out by using the statistical software (spss 15.0; SPSS Inc., Chicago, IL, USA). Results: Symptoms of voiding dysfunction were reported by 33.1% of patients and 22.4% had urodynamically diagnosed voiding dysfunction. The mean DWT in symptomatic women was not statistically different from the mean DWT in those without symptoms. URA and OCO of symptomatic women were significantly different from those of asymptomatic women (P < 0.01). DWT was not associated with parameters of voiding function, URA or OCO. Conclusions: Contrary to the situation in men, increased DWT in women does not seem to be associated with symptoms or signs of voiding dysfunction. Therefore, DWT cannot be used as a predictor of voiding difficulty in women. © 2009 The Royal Australian and New Zealand College of Obstetricians and Gynaecologists.